A method of operating a work vehicle according to a maximum allowable swing speed

Abstract

A method of operating a work vehicle 10 comprising a swing apparatus 11 comprising an arm arrangement 14. A control system stores or receives an initial maximum allowable swing speed, which is updated

Description

Technical Field The present disclosure relates to a method of operating a work vehicle according to a maximum allowable swing speed, a controller configured to perform such a method and a work vehicle configured to be operated in accordance with such a method. Background Work vehicles or machines such as excavators or backhoe loaders have various degrees of freedom. One such degree of freedom is swing, which refers to the rotation of the main body relative to its undercarriage, or the rotation of an arm arrangement relative to the main body. Various features affect the swing characteristics, including the swing speed and swing acceleration of the work vehicle. For example, the position of its components, such as the position of an arm arrangement and / or tool, may alter a moment of inertia. This may affect the rate at which the swing speed can be increased or decreased. In addition, a configuration of the work vehicle, such as the type of tool attached, may affect the moment of inertia and therefore the rate at which the swing speed can be increased or decreased. It is important that the swing speed can be reduced to zero within a certain distance or time to allow an operator to stop the swing quickly, such as when becoming aware of an obstruction or hazard within a safe distance. In addition to this general requirement, European regulation EN 474 requires that a work vehicle, specifically an excavator, must be able to perform a 180-degree swing with a 100% control input and then subsequently stop within a predetermined distance. The regulation previously required that this be accomplished with the most common configuration of the work vehicle. The European regulation EN 474 has been updated to require that a work vehicle must be able to stop within the safe distance in every available configuration. Summary An object of the present disclosure may be to provide a method of limiting the maximum operational swing speed of a work vehicle for allowing the work vehicle to reduce its swing speed to zero in a safe distance. A further object is to ensure that such a method operates across the different authorised configurations of the work vehicle. In addition, a further object is to ensure that such a method does not overly reduce the swing speed of the work vehicle. If the swing speed is overly reduced, an operator may notice this during single function and some multi-function operations. The present disclosure is generally directed towards limiting the maximum operational swing speed of a swing apparatus of a work vehicle, such as the main body of an excavator, so that it can stop within a safe distance and / or angle. A calibration process is used to determine the appropriate maximum allowable swing speed. The calibration process comprises performing a swing rotation at a calibration swing speed and then measuring the angular displacement while the swing speed reduces to zero. This is repeated at various swing speeds until the highest swing speed which still results in an acceptable angular displacement, while the swing speed reduces to zero, is found. The maximum operational swing speed is then set as this swing speed. The present disclosure provides a method of operating a work vehicle comprising a swing apparatus rotatable about a swing axis. The swing apparatus comprises an arm arrangement comprising a boom and a stick. The work vehicle further comprises a swing angle sensor for generating swing angle data indicative of a swing angle of the swing apparatus. The method comprises, by a control system, storing and / or receiving an initial maximum allowable swing speed of the swing apparatus rotating about the swing axis and updating the maximum allowable swing speed based upon a user-initiated calibration process. The user-initiated calibration process comprises: 1) performing a predetermined test angular displacement of the swing apparatus about the swing axis at a calibration swing speed; 2) reducing a swing speed of the swing apparatus to zero; 3) measuring an angular stopping displacement of the swing apparatus, using the swing angle sensor whilst the swing speed is reduced to zero; 4) if the angular stopping displacement is not within a predetermined maximum angular stopping displacement, repeating steps 1) to 4) with an updated calibration swing speed; and 5) if the angular stopping displacement is within the predetermined maximum angular stopping displacement, determining the maximum allowable swing speed based on the calibration swing speed. The method further comprises limiting a maximum operational swing speed of the swing apparatus to the updated maximum allowable swing speed. There is also provided a controller for controlling a work vehicle comprising a swing apparatus rotatable about a swing axis. The swing apparatus comprises an arm arrangement comprising a stick and a boom. The work vehicle further comprises a swing angle sensor for generating swing angle data indicative of a swing angle of the swing apparatus. The controller is configured to store and / or receive an initial maximum allowable swing speed of the swing apparatus rotating about the swing axis and update the maximum allowable swing speed based upon a user-initiated calibration process. The user-initiated calibration process comprises: 1) performing a predetermined test angular displacement of the swing apparatus about the swing axis at a calibration swing speed; 2) reducing a swing speed of the swing apparatus to zero; 3) measuring an angular stopping displacement of the swing apparatus, using the swing angle sensor whilst the swing speed is reduced to zero; 4) if the angular stopping displacement is not within a predetermined maximum angular stopping displacement, repeating steps 1) to 4) with an updated calibration swing speed; and 5) if the angular stopping displacement is within the predetermined maximum angular stopping displacement, determining the maximum allowable swing speed based on the calibration swing speed. The controller is further configured to limit a maximum operational swing speed of the swing apparatus to the updated maximum allowable swing speed. There is also provided a work vehicle comprising a swing apparatus rotatable about a swing axis. The swing apparatus comprises an arm arrangement comprising a boom and a stick. The work vehicle further comprises a swing angle sensor for generating swing angle data indicative of a swing angle of the swing apparatus and a control system comprising the controller described above. By way of example only, embodiments according to the present disclosure are now described with reference to, and as shown in, the accompanying drawings. Brief Description of the Drawings Figure 1 is a side elevation of an embodiment of a system of the present disclosure; Figure 2 is a top elevation of the system of Figure 1; Figure 3 is a schematic of a control system of the system of Figure 1; Figure 4 is a flow diagram illustrating a method of limiting a maximum operational swing speed of a swing apparatus according to the present disclosure; Figure 5 is a flow diagram illustrating a further embodiment of the method of Figure 4; Figure 6 is a flow diagram illustrating a further embodiment of the method of Figure 4; and Figure 7 is a flow diagram illustrating a user-initiated calibration process according to the present disclosure. Detailed Description The ensuing description provides preferred exemplary embodiment(s) only, and is not intended to limit the scope, applicability or configuration of the invention. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements, including combinations of features from different embodiments, without departing from the scope of the invention. Specific details are given in the following description to provide a thorough understanding of the embodiments. However, it will be understood by one of ordinary skill in the art that embodiments may be practised without these specific details. For example, well-known circuits, processes, algorithms, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the embodiments. Also, it is noted that the embodiments may be described as a process which is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. Although a flowchart may describe the operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be re-arranged. A process is terminated when its operations are completed, but could have additional steps not included in the figure. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination corresponds to a return of the function to the calling function or the main function. Moreover, as disclosed herein, the term "storage medium" may represent one or more devices for storing data, including read only memory (ROM), random access memory (RAM), magnetic RAM, core memory, magnetic disk storage mediums, optical storage mediums, flash memory devices and / or other machine readable mediums for storing information. The term "computer-readable medium" includes, but is not limited to, portable or fixed storage devices, optical storage devices, wireless channels and various other mediums capable of storing, containing or carrying instruction(s) and / or data. Furthermore, embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. When implemented in software, firmware, middleware or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine readable medium such as storage medium. A processor(s) may perform the necessary tasks. A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment may be coupled to another code segment or a hardware circuit by passing and / or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc. It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and / or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and / or configurations discussed. Moreover, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed interposing the first and second features, such that the first and second features may not be in direct contact. Figure 1 illustrates an embodiment of a system 9 comprising a work vehicle 10, in this case an excavator. The work vehicle 10 may be any suitable type of work vehicle 10, including multi-purpose work vehicles, such as excavators, backhoes, loaders, dozers, shovels, fellers, harvesters, material handlers and other such work vehicles. The work vehicle 10 comprises a swing apparatus 11 and may comprise a swing base 13. The swing apparatus 11 comprises an arm arrangement 14. The swing apparatus may comprise a main body 12. The swing base 13 may comprise an undercarriage 32 and / or a platform. The undercarriage 32 may comprise wheels or tracks 20. The main body 12 may comprise a cab 8 for an operator and a power unit (not shown) therein for providing power to the wheels or tracks 20. The swing apparatus 11 may be attached to the swing base 13 via a swivel mount 31. The swivel mount 31 may allow the swing apparatus 11 to rotate in relation to the swing base 13. The swivel mount 31 may comprise a slip ring or a slewing ring. The swivel mount 31 may be referred to as a swivel. The swivel mount 31 may be the rotation connection part of swing apparatus 11 and the swing base 13. Rotation of the swing apparatus 11 relative to the swing base 13 may be actuated using a swing actuator 30. The swing actuator 30 may comprise a hydraulic motor or a hydraulic swivel. The swing apparatus 11 is rotatable about a swing axis 33. The swing apparatus 11 may be able to rotate by 360 degrees relative to the swing base 13 about the swivel mount 31 and / or swing axis 33. The swing axis 33 may be perpendicular to the swing base 13 and / or may be perpendicular to a horizontal plane or the ground when the work vehicle 10 is on a level surface. The swing axis 33 may be a central axis of the swivel mount 31 and may be the axis of rotation of the swing apparatus 11 relative to the swing base 13 at the swivel mount 31. The arm arrangement 14 comprises a boom 16 and a stick 17. The boom 16 and a stick 17 may be pivotally attached to one another. The boom 16 may be pivotally attached to the main body 12 at a first end of the boom 16. The stick 17 may be pivotably attached to the boom 16 at a second end of the boom 16 and a first end of the stick 17. A tool 15 may be connected to the arm arrangement 14. The tool 15 may be pivotably attached to the stick 17 at a second end of the stick 17. The arm arrangement 14 may comprise at least one hydraulic actuator 18, 19, 21 for controlling the orientation thereof. In particular, the arm arrangement 14 may comprise the boom hydraulic actuator 18 for controlling the orientation and movement of the boom 16. The arm arrangement 14 may comprise a stick hydraulic actuator 19 for controlling the orientation and movement of the stick 17. The arm arrangement 14 may comprise a tool hydraulic actuator 21 for controlling the orientation and movement of the tool 15. The tool 15 may be of any suitable type. The tool 15 may, for example, be a bucket as illustrated or may be a grapple, tiltable bucket, tilt rotator, hammer, handling arm, multiprocessor, pulveriser, saw, shears, blower, grinder, tiller, trencher, winch, auger, broom, cutter, planer, delimber, felling head, mulcher, or rake. The tool 15 may comprise a spray head or the like for providing a water spray during operation of the work vehicle 10, for example for dust suppression. The fluid may be pressurised hydraulic fluid, water or the like. The work vehicle 10 may be operable in, configurable in and / or comprise at least one configuration. The configuration may refer to one or more of a swing apparatus 11 measurement; a swing base 13 measurement; a boom 16 measurement; a stick 17 measurement; a main body 12 measurement; a cab 8 measurement; a tool 15 measurement; and / or a type of tool 15. The aforementioned measurements may be a dimension measurement and / or a weight measurement. The dimension measurement may be a length, a width, a depth, an area, and / or a volume. The weight measurement may be a weight or a mass. The work vehicle 10 may be operable in, configurable in, and / or comprise a plurality of configurations with different inertias, including a configuration having the greatest moment of inertia. In the greatest inertia configuration, the type of tool 15 may be a tool with a greater mass than other available tools and / or the arm arrangement 14 may comprise components of a greater length, weight and / or mass. The work vehicle 10 may be orientable in and / or comprise a component position. The component position may comprise a boom 16 position; a stick 17 position; and / or a tool 15 position. The position may be defined by a component angle. The position may be defined by a component cylinder extension. The component position may comprise an arm arrangement 14 position, or a linkage position. Each configuration of the work vehicle 10 may be capable of having a plurality of different component positions. The boom 16 may comprise a boom axis 35. The boom axis 35 may be an axis parallel to the direction along which the boom 16 extends for a majority of its length. The stick 17 may comprise a stick axis 37. The stick axis 37 may be an axis parallel to the direction along which the stick 17 extends for a majority of its length. A boom angle 39 may be the angle between the boom axis 35 and the swing axis 33. A stick angle 41 may be the angle between the boom axis 35 and the stick axis 37. The boom angle 39 and / or stick angle 41 may be used to define the component position. Global angles wherein the various axes are measured relative to the horizontal may be used to define the component position. The boom, stick and tool hydraulic actuators 18, 19, 21 may each comprise a hydraulic cylinder and a piston rod. Hydraulic fluid may be supplied to the actuators to displace the rod relative to the cylinder. The boom hydraulic actuator 18 may comprise a boom hydraulic piston rod (not shown). The stick hydraulic actuator 19 may comprise a stick hydraulic piston rod 5. As the stick hydraulic piston rod and / or the stick hydraulic piston rod 5 are extended, the component position may change. A boom hydraulic piston rod extension and / or a stick hydraulic piston rod extension may be used to define the component position. Figure 2 provides an illustration of the work vehicle 10 of Figure 1 in plan view, in which the swing axis 33 is illustrated as a point. The work vehicle may comprise a reference travel axis 43. The reference travel axis 43 may be substantially horizontal to the ground 33, lie in the same plane as the horizontal, and may pass through and / or be perpendicular to the swing axis 33. The reference travel axis 43 may be parallel to the direction the work vehicle travels when the tracks 20 are actuated simultaneously with the same input. The reference travel axis 43 may be parallel to a direction the work vehicle 10 travels when a forward command is given. The work vehicle 10 may comprise a swing apparatus axis 45. The swing apparatus axis 45 may lie in the same plane as the horizontal, and / or may lie in the same plane as the reference travel axis 43. The swing apparatus axis 45 may be parallel to a direction of extension of the arm arrangement 14 (as shown in Figure 2) and may pass through and / or be perpendicular to the swing axis 33. The swing apparatus axis 45 may be parallel to a direction the operator faces while sitting in the cab 8. The work vehicle 10 may comprise a swing angle 6. The swing angle 6 may be defined as the angle measured between the reference travel axis 43 and the swing apparatus axis 45. When the swing angle 6 is increased or decreased, the swing apparatus 11 may rotate around the swing axis 33 at a swing speed a). The swing apparatus 11 may rotate relative to the swing base 13 at a swing speed co. The swing apparatus 11 may rotate around the swing axis 33 in a swing direction (clockwise or anti clockwise). The swing speed to may be a swing velocity comprising the swing direction. The work vehicle 10 may comprise a work vehicle fluid circuit (not shown) around which fluid may be circulated. The work vehicle 10 may comprise a controller 51 for controlling the work vehicle fluid circuit automatically or based upon inputs received from at least one input device 6 (shown in Figure 1). The at least one input device 6 may comprise one or more of a joystick, a display 57, a touch screen, a button, or any suitable input device. The least one input device 6 may be used to operate the work vehicle 10. The work vehicle 10 may be operated to change the component position. The work vehicle fluid circuit may be connected to the at least one hydraulic actuator 18, 19, 21. Changing the component position may comprise controlling the at least one hydraulic actuator 18, 19, 21 for pivoting of the arm arrangement 14 and the tool 15. The work vehicle 10 may be operated to increase or decrease the swing angle 6. The work vehicle fluid circuit may be connected to the swing actuator 30 and a swing brake 34 for controlling the swing of the swing apparatus 11 relative to the swing base 13. The swing speed co may be controlled and / or affected by the least one input device 6. When an input to the least one input device 6 indicates an increase, the swing speed ¢0 may increase. When the input to the input device 6 indicates a decrease, the swing speed to may decrease. When an input of 100% speed is provided to the at least one input device 6, the swing speed co may increase towards a maximum operational swing speed of the work vehicle. When an input of 0% speed is provided to the at least one input device, the swing speed co may decrease towards a zero swing speed co, or the swing speed co may remain at zero. In order to decrease the swing speed co, the system 9 may apply the swing brake 34 and / or may stop the application of torque by the swing actuator 30. The system 9 may apply the swing brake 34 to the swivel mount 31 and / or the swing actuator 30. The swing brake 34 may apply a brake torque xb in the opposite direction to the swing direction. The swing brake 34 may cause the swing speed to to decrease. The swing brake 34 may cause the swing speed to to decrease to zero. For reasons of safety, it may be beneficial that the system 9 is able to reduce the swing speed to to zero within a predetermined maximum angular stopping displacement 0S. In addition, there are regulatory requirements that the system 9 is able to reduce the swing speed to to zero within the predetermined maximum angular stopping displacement 0S. The predetermined maximum angular stopping displacement 0S may be a 90-degree angular displacement. It may be required that the system 9 is able to reduce the swing speed to to zero from the maximum operational swing speed within a predetermined angular displacement. It may be required that the system 9 is able to reduce the swing speed to to zero from the maximum operational swing speed within an angular displacement of 90 degrees. It may be required that the system 9 is able to reduce the swing speed to to zero after performing a safety angular displacement 0safety. The safety angular displacement 0safety may be 180 degrees. A requirement that the system 9 is able to reduce the swing speed to to zero after performing the safety angular displacement 6safety ensures that even in the configuration of the greatest inertia, which may only reach the maximum operational swing speed at the end of the safety angular displacement 0safety, must also stop within the predetermined maximum angular stopping displacement 0S. It may be required that the system 9 is able to reduce the swing speed m to zero within the predetermined maximum angular stopping displacement 0S regardless of the configuration and / or component position of the work vehicle 10. Instead of the predetermined maximum angular stopping displacement 0S, a different metric, such as a predetermined maximum stopping time, may be used. The swing apparatus 11 comprises a moment of inertia J. The moment of inertia J is the physical quantity of a body which represents the body’s resistance to a change in angular speed. The moment of inertia ] affects the ability of the system 9 to reduce the swing speed <a to zero within the predetermined maximum angular stopping displacement 0S. A larger moment of inertia / results in a larger angular displacement required to reduce the swing speed a) to zero and results in a lower swing speed being required to so that the swing speed to can be reduced to zero within the predetermined maximum angular stopping displacement 0S. The moment of inertia J may be linked to the brake torque zb and an angular deceleration experienced during braking by the following formula: rb = J a Where a is the angular deceleration and is the rate of change of swing speed <z>. The moment of inertia / around an axis, may be defined as the sum of the products obtained by multiplying the mass of each particle of matter in a given body by the square of its distance from the axis. The moment of inertia J of the swing apparatus 11 may be higher when a tool 15 with a larger mass is attached to the arm arrangement 14 and may be lower when a tool 15 with a smaller mass is attached to the arm arrangement 14. The moment of inertia J of the swing apparatus 11 may be higher when the component position is such that the arm arrangement 14 extends by a longer distance from the swing axis 33 and may be lower when the component position is such that the arm arrangement 14 extends by a shorter distance from the swing axis 33. The moment of inertia ] may constantly change when the work vehicle 10 is in use and is therefore not a known design parameter of the work vehicle 10. The system 9 may comprise a control system 50, which may be configured to perform the methods of the present disclosure. As illustrated in Figure 3, the control system 50 may comprise the controller 51, which may comprise a memory 53, which may store instructions or algorithms in the form of data, and a processing unit 55, which may be configured to perform operations based upon the instructions. The controller 51 may be of any suitable known type and may comprise an engine control unit (ECU) or the like. The memory 53 may comprise any suitable computer-accessible or non-transitory storage medium for storing computer program instructions, such as RAM, SDRAM, DDR SDRAM, RDRAM, SRAM, ROM, magnetic media, optical media and the like. The processing unit 55 may comprise any suitable processor capable of executing memory-stored instructions, such as a microprocessor, uniprocessor, a multiprocessor and the like. The controller 51 may further comprise a graphics processing unit for rendering objects for viewing on the display 57 of the control system 50. The controller 51 may also be in communication with least one work vehicle communication module 59 for transferring data with an external computing system 61 via a wired or wireless network 63 (such as Ethernet, fibre optic, satellite communication network, broadband communication network, cellular, Bluetooth). The external computing system 61 may comprise computing systems, processors, servers, memories, databases, control systems and the like. As summarised in Figure 3, the system 9 may comprise at least one system actuator 4. The at least one system actuator 4 may comprise one or more of the boom, stick and tool hydraulic actuators 18, 19, 21, the swing actuator 30 and the swing brake 34. The system 9 comprises a swing angle sensor 71. The swing angle sensor 71 is for generating swing angle data indicative of a swing angle 0 of the swing apparatus 11. The swing angle sensor 71 may be a Hall sensor. The swing angle sensor 71 may be a Hall IC sensor. The swing angle sensor 71 may be mounted to the swing apparatus 11. The swing angle sensor 71 may be mounted to the swivel mount 31. The system 9 may comprise at least one sensor 7. The at least one sensor 7 may comprise one or more of the swing angle sensor 71, at least one movement or acceleration sensor 73, at least one component position sensor 75, a boom pressure sensor 77, an inertial measurement unit (IMU), an accelerometer, a gyroscope, a magnetometer, and a pressure sensor. In order to reduce complexity of the work vehicle 10, it may be beneficial to reduce the number of sensors necessary. For example, it may be beneficial for the work vehicle 10 to not include the at least one movement or acceleration sensor 73 if possible. The controller 51 may be communicatively connected (via a wired or wireless connection) to the power unit, and any of the at least one system actuator 4 and / or at least one sensor 7 for providing control signals thereto and receiving sensor signals therefrom in order to control the operation of the work vehicle 10. The controller 51 may communicate with the input device 6, for receiving an input and controlling the work vehicle 10. The input device 6 may be in communication with the controller 51 for controlling the actuation of the swing actuator 30 and / or swing brake 34 to adjust the swing speed cd and / or adjust the swing angle 0 of the swing apparatus 11. The input device 6 may increase or decrease the swing speed cd of the swing apparatus 11 relative to the swing base 13. The controller 51 may receive operating condition data indicative of at least one operating condition of the work vehicle 10 by being communicatively coupled with the at least one sensor 7 and the at least one system actuator 4. The controller 51 may process the received operating condition data to determine further operating condition data and may store the operating condition data on the memory 53. The at least one operating condition and operating condition data may comprise at least one of: - The swing angle e of the work vehicle 10, relative to the reference travel axis 43 (as shown in Figure 2). The control system 50 may comprise the swing angle sensor 71 for determining the swing angle 6 of the work vehicle 10 the swing angle sensor 71 may be mounted to the swing apparatus 11; - The swing speed w of the work vehicle 10. The control system 50 may comprise at least one movement or acceleration sensor 73 for determining the swing speed to of the work vehicle 10; - The component position of the work vehicle 10. The control system 50 may comprise at least one component position sensor 75 for determining the component position of the work vehicle 10. The at least one component position sensor 75 may be mounted to the swing apparatus 11. The at least one component position sensor 75 may comprise at least one inertial measurement unit (IMU); - The boom position; stick position; and / or tool position of the work vehicle 10. The control system 50 may comprise at least one component position sensor 75 attached to the boom 16; stick 17 and / or tool 15 for determining the boom 16; stick 17; and / or tool 15 position of the work vehicle 10. The at least one component position sensor 75 may comprise at least one inertial measurement unit (IMU) attached to the boom 16; stick 17 and / or tool 15; - A component movement and / or acceleration of the work vehicle 10. The control system 50 may comprise at least one movement or acceleration sensor 73 for determining the component movement and / or acceleration of the work vehicle 10. The at least one movement or acceleration sensor 73 may be mounted to the swing apparatus 11. The at least one movement or acceleration sensor 73 may be at least one accelerometer; - A boom movement and / or acceleration; stick movement and / or acceleration; and / or tool movement and / or acceleration. The control system 50 may comprise at least one movement or acceleration sensor 73 attached to the boom 16; stick 17 and / or tool 15 for determining the boom 16; stick 17; and / or tool 15 movement and / or acceleration. The at least one movement or acceleration sensor 73 may comprise at least one accelerometer attached to the boom 16; stick 17 and / or tool 15; - The boom and / or stick angle of the work vehicle 10. The control system 50 may comprise the component position sensor 75, such as the IMU for determining the boom and / or stick angle of the work vehicle 10; - The boom and / or stick hydraulic piston rod extension of the work vehicle 10. The control system 50 may comprise the component position sensor 75, such as the IMU for determining the boom and / or stick hydraulic piston rod extension of the work vehicle 10; - A boom head end pressure of the work vehicle 10.The control system 50 may comprise the boom pressure sensor 77 within the boom hydraulic cylinder 18, for determining the boom head end pressure of the work vehicle 10.; - The configuration of the work vehicle 10. The configuration of the work vehicle 10 may be input by the operator via the at least one input device 6; stored on the memory 53; and / or detected automatically using work vehicle sensors; - The brake torque zb of the swing brake 34 of the work vehicle 10. The brake torque tb may be input by the operator via at least one input device 6, stored on the memory 53 and / or estimated based upon a change in the component movement and / or acceleration upon application of the swing brake 34. The brake torque rb applied at any time may be based upon the input to the at least one input device 6. A 0% input to the at least one input device 6 may result in a maximum brake torque Tbmax being applied by the swing brake 34; - An actuation torque za of the swing actuator 30 of the work vehicle 10. The actuation torque ra may be input by the operator via at least one input device 6, stored on the memory 53 and / or estimated based upon a change in the component movement and / or acceleration upon application of the swing actuator 30. The actuation torque ra may be based upon the input to the at least one input device 6; - The maximum operational swing speed of the work vehicle. The maximum operational swing speed of the work vehicle may be determined according to the methods of this disclosure; - A maximum allowable swing speed o)max of the work vehicle. The maximum allowable swing speed o>max of the work vehicle may be determined according to the methods of this disclosure; - A calibration swing speed a)caUbrate. The calibration swing speed wcaiibrate may be determined according to the methods of this disclosure. The calibration swing speed ^calibrate may be updated during the method of this disclosure and may not take a single value. - The predetermined maximum angular stopping displacement 9S. The predetermined maximum angular stopping displacement 9S may be input by the operator via at least one input device 6 and / or stored on the memory 53. The predetermined maximum angular stopping displacement 0s may be set by a regulatory and / or a safety requirement; - A test angular displacement 0test. The test angular displacement 6test may be equal to the safety angular displacement 0safety The test angular displacement etest may be input by the operator via at least one input device 6 and / or stored on the memory 53; - An angular stopping displacement estop. The angular stopping displacement 0stop is measured whilst the swing speed is reduced to zero. The angular stopping displacement 0stop is measured using the swing angle sensor 71. The operating condition data collected by the control system 50 may be transferred to the external computing system 61, which may perform the method of the present disclosure. Thus, the control system 50 may be considered in the present disclosure to comprise the external computing system 61, which may have instructions stored thereon for performing the methods disclosed herein in a similar manner to the controller 51. As shown in Figure 4, a method of operating the work vehicle 10 comprises storing and / or receiving an initial maximum allowable swing speed comax,init ofthe swin9 apparatus 11 rotating about the swing axis 33; updating the maximum allowable swing speed comax based upon a user-initiated calibration process; and limiting a maximum operational swing speed of the swing apparatus to the updated maximum allowable swing speed comax. The method is performed by the control system 50. If the work vehicle 10 is configurable in a plurality of different configurations of differing inertias, the initial maximum allowable swing speed comaX / init may be based upon the predetermined maximum angular stopping displacement 9S and a rate of deceleration of the swing apparatus 11 in the configuration having the greatest inertia. The initial maximum allowable swing speed o)maXiinit may be the swing speed co from which the swing apparatus 11 can slow to zero within the predetermined maximum angular stopping displacement 6S, given the rate of deceleration of the swing apparatus 11 in the configuration having the greatest inertia. A limit of the initial maximum allowable swing speed (amaXiinit may ensure that the work vehicle 10 can stop within a safe distance regardless of its configuration prior to the user-initiated calibration process being performed. Updating the maximum allowable swing speed o)max based upon the user-initiated calibration process may allow the maximum allowable swing speed o)max to be increased when a configuration other than the configuration having the greatest inertia is used. Updating the maximum allowable swing speed c»max may ensure that the swing speed of the work vehicle 10 is not overly reduced. The user-initiated calibration process may be performed at a worksite. The user-initiated calibration process may be performed by an operator who will subsequently control the work vehicle 10 to perform work on the worksite. The user-initiated calibration process may be performed before or after operation of the work vehicle 10 on the worksite. As shown in Figure 5, the method may further comprises generating an alert to the operator indicating that the user-initiated calibration process is required. The alert may be generated if the work vehicle 10 is used without performing the user-initiated calibration process. The alert may be generated every time the configuration of the work vehicle 10 is changed. A change of the configuration of the work vehicle 10 may be detected by the at least one sensor 7 of the work vehicle 10. As shown in Figure 6, the method may further comprise saving the updated maximum allowable swing speed o)max to a datafile corresponding to the current configuration of the work vehicle 10. The updated maximum allowable swing speed o)max may be saved to the memory 53. The configuration of the work vehicle 10 may be changed and the work vehicle 10 may be operated in the changed configuration. The configuration of the work vehicle 10 may be changed back to a previous configuration. The previous configuration may correspond to the configuration of the work vehicle 10 wherein the updated maximum allowable swing speed o)max was saved. The maximum operational swing speed of the swing apparatus 11 may be limited to the saved maximum allowable swing speed. The configuration of the work vehicle 10 may be automatically detected by sensors 7 of the work vehicle 10. The configuration of the work vehicle 10 may be inputted by the operator. Up to ten, twenty, or thirty different updated maximum allowable swing speed o)max may be saved. Saving the updated maximum allowable swing speed o)max to a datafile corresponding to the current configuration of the work vehicle 10 may allow the appropriate updated maximum allowable swing speed ci)max to be used for a given configuration without repeating the user-initiated calibration process every time said configuration is used. As shown in Figure 7, the user-initiated calibration process comprises: 1) performing a predetermined test angular displacement 0test of the swing apparatus 11 about the swing axis 33 at a calibration swing speed (jd calibrated 2) reducing the swing speed of the swing apparatus 11 to zero; 3) measuring the angular stopping displacement 0stop of the swing apparatus 11, using the swing angle sensor 71 whilst the swing speed w is reduced to zero; 4) if the angular stopping displacement 0stop is not within the predetermined maximum angular stopping displacement 0S, repeating steps 1) to 4) with an updated calibration swing speed ^calibrated and 5) if the angular stopping displacement 0stop is within the predetermined maximum angular stopping displacement 0S, determining the maximum allowable swing speed Mmax based on the calibration swing speed w calibrate- The predetermined test angular displacement 0test may be performed with a 100% control input to the swing actuator 30 of the swing apparatus 11. Reducing the swing speed a) of the swing apparatus 11 to zero may be performed by applying a maximum brake torque Tb>max of the swing brake 34 to the swing apparatus 11. Reducing the swing speed ro of the swing apparatus 11 to zero may be performed immediately after performing the predetermined test angular displacement 0test. Measuring the angular stopping displacement 6stop may occur after performing the predetermined test angular displacement 0test. Measuring the angular stopping displacement 6stop may occur while applying a maximum brake torque rbimax of the swing brake 34. The calibration swing speed cbcaUbrate may be set initially as the initial maximum allowable swing speed cbmaxinit. Initially setting the calibration swing speed McaUbrate as the initial maximum allowable swing speed MmaXiinit may ensure that the work vehicle 10 does not contravene a safety and / or regulatory requirement when starting the user-initiated calibration process. Updating the calibration swing speed (acaubrate may include updating the calibration swing speed ^calibrate such that the updated calibration swing speed cbcaiibrate is higher than the previous calibration swing speed ^calibrate- The calibration swing speed ^calibrate may be updated by a fixed amount each time steps 1) to 4) are carried out. The calibration swing speed ojcailbrate may be updated such that the difference between the updated calibration swing speed (^calibrate and the previous calibration swing speed (acaiibrate is based on the difference between the angular stopping displacement 6stop and the predetermined maximum angular stopping displacement 6S. Basing the updated calibration swing speed cocaiibrate on the difference between the angular stopping displacement 6stop and the predetermined maximum angular stopping displacement 9S may cause the calibration process to conclude and / or converge more quickly. Determining the maximum allowable swing speed Mmax based on the calibration swing speed wcaiibrate may occur when the angular stopping displacement 9stop is close to the predetermined maximum angular stopping displacement 9S. Steps 1) to 5) may be carried out a plurality of times with different calibration swing speeds calibrate- Ifa first calibration swing speed ^calibrate,! results in the angular stopping displacement estop being within the predetermined maximum angular stopping displacement es and a second calibration swing speed w calibrate^ results in the angular stopping displacement 6stop not being within the predetermined maximum angular stopping displacement es (wherein the second calibration swing speed Mcaiibrate,2 is slightly higher than the first calibration swing speed wcalibratel), then the maximum allowable swing speed i»max may be set as the first calibration swing speed Mcaiibrate l. As shown in Figure 7, the user-initiated calibration process may further comprise step 4B) after step 4). Step 4B) may comprise: 4B) if the angular stopping displacement 0stop is not within a predetermined error margin of the predetermined maximum angular stopping displacement 0S, repeating steps 1) to 4B) with an updated calibration swing speed (^calibrate- The error margin may be 1%, 2%, 5%, or 10% of the predetermined maximum angular stopping displacement 0S. Including step 4B) can ensure that the maximum allowable swing speed o)max selected is close to the highest maximum allowable swing speed which will still allow the swing speed a) to be reduced to zero within the predetermined maximum angular stopping displacement 0S after performing the safety angular displacement 0safety. As shown in Figure 7, the user-initiated calibration process may further comprise step 0) prior to step 1). Step 0) may comprise: 0) extending the arm arrangement 14 of the work vehicle 10 to a maximum extension and / or moving the tool 15 of the work vehicle 10 to a maximum distance from the swing axis 13. The arm arrangement 14 may be maintained extended at the maximum extension and / or the tool 15 may be maintained at the maximum distance from the swing axis 33 for the remainder of the user-initiated calibration process. If the extension of the arm arrangement 14 is reduced, the user-initiated calibration process may be paused and resumed when the arm arrangement 14 is extended back to the maximum extension. Including step 0) may place the work vehicle 10 in a component position of greatest inertia, for a given configuration, during the user-initiated calibration process. This may ensure that the updated maximum allowable swing speed o)max allows the swing speed to be reduced to zero within the predetermined maximum angular stopping displacement 9S after performing the safety angular displacement 9safety regardless of the component position of the work vehicle 10. If the work vehicle 11 comprises at least one component position sensor 75 mounted to the swing apparatus 11, the updated maximum allowable swing speed o>max and / or the initial maximum allowable swing speed a)maxdnit may be modified to determine a modified maximum allowable swing speed wmaX:mod based upon work vehicle component position data from the at least one component position sensor 75. The modified maximum allowable swing speed d)maXimod may be determined as the swing speed to from which the swing apparatus 11 will slow to zero within the predetermined maximum angular stopping displacement 9S given the work vehicle component position data and the updated maximum allowable swing speed Mmax. The modified maximum allowable swing speed a>max>mod may be determined by comparing the component position data, updated maximum allowable swing speed Mmax, and the predetermined maximum angular stopping displacement 9S to a look up table or map to find the appropriate modified maximum allowable swing speed ^max,mod- The look up table or map may be prepared via experimentation and / or empirical methods to find the appropriate modified maximum allowable swing speed a)max>mod for a given component position, updated maximum allowable swing speed Mmax and the predetermined maximum angular stopping displacement 9S. If the work vehicle 11 comprises a boom actuator 18, and at least one boom head pressure sensor 77 mounted to the boom actuator 18, the updated maximum allowable swing speed o)max and / or the initial maximum allowable swing speed a>maX:init may be modified to determine a modified maximum allowable swing speed <omaxmod based upon boom head pressure data from the at least one boom head pressure sensor 77. The modified maximum allowable swing speed wmax,mod may be determined as the swing speed co from which the swing apparatus 11 will slow to zero within the predetermined maximum angular stopping displacement 9S given the boom head pressure data and the updated maximum allowable swing speed wmax. The modified maximum allowable swing speed Mmax,mod may be determined by comparing the boom head pressure data, updated maximum allowable swing speed Umax, ar|d the predetermined maximum angular stopping displacement 6S to a look up table or map to find the appropriate modified maximum allowable swing speed ^max.mod- The look up table or map may be prepared via experimentation and / or empirical methods to find the appropriate modified maximum allowable swing speed ^max.mod for a given boom head pressure, updated maximum allowable swing speed Mmax and the predetermined maximum angular stopping displacement ds. The use of the modified maximum allowable swing speed <omaxmod based upon work vehicle component position data and / or boom head pressure data may allow the maximum allowable swing speed to take into account the change in moment of inertia J due to a change in component position. The use of the modified maximum allowable swing speed <omaxmod may improve the swing performance of the work vehicle 10 by allowing a higher speed when the moment of inertia / is reduced. The operator may provide commands to the control system 50 to perform at least steps 1) and 2) of the user-initiated calibration process. The operator may provide commands to the control system 50 to perform at least one of steps 0), 1), 2), 4), and 4B). The control system 50 may perform at least steps 3) and 5) without further commands from the operator. The control system 50 may provide command prompts to the operator indicating the steps the operator should follow. The command prompts may be displayed on the display 57. The operator needing to provide inputs for steps of the user-initiated calibration process may improve the safety of the process since the operator will be actively involved throughout and may stop performing the user-initiated calibration process if it becomes unsafe (for example if an unauthorised person or object comes near the vehicle during the user-initiated calibration process). The control system 50 may perform all the steps of the user-initiated calibration process upon the operator providing a calibration command, without further inputs from the operator. The control system 50 performing all the steps of the user-initiated calibration process may improve the ease with which the user-initiated calibration process can be performed by the operator. The operator may be able to abort the user-initiated calibration process if they deem it to become unsafe. The method may further comprise the control system 50 rotating the swing apparatus 11 about the swing axis 33 at a swing speed to equal to or less than the maximum operational swing speed. The method may further comprise the control system 50 overriding a user command to rotate the swing apparatus 11 around the swing axis 33 at a swing speed m greater than the maximum operational swing speed. Overriding the user command may comprise receiving a user input to perform a rotation at a swing speed to greater than the maximum operational swing speed and outputting a command to the swing actuator 30 to perform a rotation at a swing speed to equal to or less than the maximum operational swing speed. Industrial Applicability The method may thus use the user-initiated calibration process to determine an appropriate maximum allowable swing speed Mmax. By the user-initiated calibration process, the requirement to reduce the swing speed to to zero after performing a safety angular displacement 9safety within the predetermined maximum angular stopping displacement 9S may be fulfilled regardless of the configuration of the work vehicle 10. In addition, an appropriate maximum allowable swing speed to,nax for this specific configuration is determined. Overly limiting the swing speed to due to a higher moment of inertia / of other configurations does not occur. The maximum allowable swing speed o)max is based on the current configuration and so may be maximised. This ensures that the work vehicle 10 is able to reduce its swing speed to to zero in a safe distance, such as the predetermined maximum angular stopping displacement 9S, across different configurations of the work vehicle 10. In addition, the swing performance of the work vehicle 11 is not unduly affected as it is at a maximum safe speed for the current configuration. This is accomplished with only the swing angle sensor 71 and so the number of sensors on the work vehicle 10 can be minimized. If the method includes saving the updated maximum allowable swing speed o>max to a datafile corresponding to the current configuration of the work vehicle 10 then the appropriate updated maximum allowable swing speed wmax to be used for a given configuration without repeating the user-initiated calibration process every time said 5 configuration is used. This may improve the performance of the work vehicle 10 as the user-initiated calibration process will only be necessary when a new configuration is used.

Claims

1. A method of operating a work vehicle comprising:a swing apparatus rotatable about a swing axis, the swing apparatus comprising an arm arrangement comprising a boom and a stick, and5 a swing angle sensor for generating swing angle data indicative of a swing angleof the swing apparatus,the method comprising, by a control system:storing and / or receiving an initial maximum allowable swing speed of the swing apparatus rotating about the swing axis;10 updating the maximum allowable swing speed based upon a user-initiatedcalibration process comprising:1) performing a predetermined test angular displacement of the swing apparatus about the swing axis at a calibration swing speed;2) reducing a swing speed of the swing apparatus to zero;15 3) measuring an angular stopping displacement of the swing apparatus,using the swing angle sensor whilst the swing speed is reduced to zero;4) if the angular stopping displacement is not within a predetermined maximum angular stopping displacement, repeating steps 1) to 4) with an updated calibration swing speed; and20 5) if the angular stopping displacement is within the predeterminedmaximum angular stopping displacement, determining the maximum allowable swing speed based on the calibration swing speed; and limiting a maximum operational swing speed of the swing apparatus to the updated maximum allowable swing speed.

252. The method of claim 1 wherein the user-initiated calibration process is performed at a worksite and / or is performed after operation of the work vehicle on a worksite.

3. The method of claim 1 or 2 wherein the method further comprises generating an alert 30 to an operator indicating that the user-initiated calibration process is required.

4. The method of any preceding claim wherein the user-initiated calibration process further comprises, after step 4):4B) if the angular stopping displacement is not within a predetermined error margin of the maximum angular stopping displacement, repeating steps 1) to 4B) with an updated calibration swing speed.5 5. The method of any preceding claim, wherein:the predetermined test angular displacement is performed with a 100% control input to a swing actuator of the swing apparatus and / orreducing the swing speed of the swing apparatus to zero is done by applying a maximum brake torque of a swing brake to the swing apparatus.

106. The method of any preceding claim, wherein the work vehicle is configurable in a plurality of different configurations of differing inertias, and the initial maximum allowable swing speed is based upon a predetermined maximum angular stopping displacement and a rate of deceleration of the swing apparatus in a configuration having the greatest15 inertia.C\J7. The method of any preceding claim, wherein the user-initiated calibration process includes updating the calibration swing speed such that the updated calibration swing speed is higher than the previous calibration swing speed.O) 208. The method of any preceding claim, wherein the user-initiated calibration process includes updating the calibration swing speed such that the difference between the updated calibration swing speed and the previous calibration swing speed is based on the difference between the angular stopping displacement and the predetermined25 maximum angular stopping displacement.

9. The method of any preceding claim, wherein the method further comprises saving the updated maximum allowable swing speed to a datafile corresponding to a current configuration of the work vehicle.3010. The method of any preceding claim, wherein the user-initiated calibration process further comprises:prior to step 1), 0) extending the arm arrangement of the work vehicle to a maximum extension and / or moving a tool of the work vehicle to a maximum distance35 from the swing axis; andmaintaining the arm arrangement of the work vehicle extended at the maximum extension and / or the tool at the maximum distance from the swing axis for the remainder of the user-initiated calibration process.5 11. The method of any preceding claim, wherein an operator provides commands to thecontrol system to perform at least steps 1) and 2) of the user-initiated calibration process.

12. The method of any preceding claim, wherein the control system performs all steps 10 of the user-initiated calibration process upon an operator providing a calibration command, without further inputs from the operator.

13. The method of any preceding claim, wherein the method further comprises, by the control system:15 rotating the swing apparatus about the swing axis at a swing speed equal to orless than the maximum operational swing speed; and / oroverriding a user command to rotate the swing apparatus around the swing axis at a swing speed greater than the maximum operational swing speed.20 14. A controller for controlling a work vehicle comprising:a swing apparatus rotatable about a swing axis, the swing apparatus comprising an arm arrangement comprising a stick and a boom, anda swing angle sensor for generating swing angle data indicative of a swing angle of the swing apparatus,25 the controller being configured to:store and / or receive an initial maximum allowable swing speed of the swing apparatus rotating about the swing axis;update the maximum allowable swing speed based upon a user-initiated calibration process comprising:30 1) performing a predetermined test angular displacement of the swingapparatus about the swing axis at a calibration swing speed;2) reducing a swing speed of the swing apparatus to zero;3) measuring an angular stopping displacement of the swing apparatus, using the swing angle sensor whilst the swing speed is reduced to zero;29 10 244) if the angular stopping displacement is not within a predetermined maximum angular stopping displacement, repeating steps 1) to 4) with an updated calibration swing speed; and5) if the angular stopping displacement is within the predetermined5 maximum angular stopping displacement, determining the maximum allowableswing speed based on the calibration swing speed; andlimit a maximum operational swing speed of the swing apparatus to the updated maximum allowable swing speed.10 15. A work vehicle comprising:a swing apparatus rotatable about a swing axis, the swing apparatus comprising an arm arrangement comprising a boom and a stick,a swing angle sensor for generating swing angle data indicative of a swing angle of the swing apparatus, and15 a control system comprising the controller of claim 14.

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