Electric excavator

Abstract

The excavator (10) comprises at electrical power system (40) with at least one motor (71) and battery mounts (63). A machine control system (90) is configured to determine the quantity of batteries (45) mounted to the battery mounts (63). The excavator (10) is operated within normal performance limits if the quantity of batteries (45) mounted to the battery mounts (63) is at least a normal battery quantity threshold. The excavator (10) is operated within adjusted performance limits if the quantity of batteries (45) mounted to the battery mounts (63) is less than the normal battery quantity threshold.

Description

[0001] Description

[0002] ELECTRIC EXCAVATOR

[0003] Technical Field

[0004] This disclosure is directed towards electrically powered excavators. The disclosure further relates to methods of designing and operating such excavators.

[0005] Background

[0006] Electric excavators and work machine typically comprise batteries therein for operating the electrical drive and other power systems. However, the batteries in such work machines may require swapping for routine maintenance, due to change in application, due to sale to a new customer with a different application, a work cycle and / or to remove a depleted batery and replace it with a fully charged batery. In addition, the work machines may be operated in a tethered mode in which power is supplied from an external power source to the electrical drive and other power systems.

[0007] Excavators and other work machine typically comprise dedicated counterweights to counterbalance the operation of work tools, particularly when the work tools pick up heavy objects. The counterweights can be added or removed depending upon the use and configuration of the work machine. However, swapping out such counterweights can be costly and time consuming for operators. In addition, counterweights are usually on the rear of the machine, where they receive contact damage during operation, removal, and installation. Often full replacement is required, which can be high cost.

[0008] Summary

[0009] An object of the present disclosure is to provide an electric excavator capable of operating without a full capacity of batteries installed. An object of the present disclosure is to provide an electric excavator with improved capabilities when operating without a full capacity of batteries installed. An object of the present disclosure is to provide an electric excavator wdth an improved counterweight solution. Further objects include providing improved methods of operating such excavators.

[0010] The present disclosure therefore provides an excavator and method in accordance with the claims. In particular, if there are less than a full capacity of batteries installed, the normal stability of the excavator can be achieved by installing counterweight packs in all battery mounts without a battery. Alternatively, if there are, for example, not enough counterweight packs available, the machine control system may operate the excavator to promote stability of the excavator, such as by reducing the speed of operation of the excavator and its components.

[0011] The excavator can still be operated with only a partial complement of batteries and / or if receiving electrical power from an external power supply via a tether. Tire machine control system may implement adjusted performance limits in which the power available to the excavator components is derated in the view' of the partial complement of batteries, for example because the installed batteries cannot supply sufficient power for the excavator components or because the installed batteries can only supply sufficient power for the excavator components for a restricted time period compared to normal operation.

[0012] The excavator can operate in conjunction with power received over a tether, either to achieve the normal performance limits alone or in addition to installed batteries, or at the adjusted performance limits if the power received over the tether is insufficient for normal performance limits. The operator also has control over the operation of the excavator, such as by selecting the performance limits to be implemented in accordance with their anticipated run time and / or power output.

[0013] Tire present disclosure provides an excavator. An electrical power system of the excavator comprises at least one motor for operating the excavator, wdiich may include at least one traction motor for driving the excavator across a terrain, and battery mounts, each batten' mount being configured to receive at least one battery for supplying power to the at least one motor. A machine control system of the excavator configured to determine the quantity of batteries mounted to the batery mounts. The machine control system operates the excavator within normal performance limits if the quantity of batteries mounted to the battery mounts is at least a normal batten' quantity threshold. The machine control system operates within the excavator within adjusted performance limits if the quantity of batteries mounted to the battery mounts is less than the normal battery quantity threshold.

[0014] The machine control system may be configured to control the power transferred by the electrical power system to the at least one motor within the normal, or adjusted, performance limits. The machine control system may control the electrical power system such that the power available to the at least one motor within the adjusted performance limits is less than the power available to the at least one motor within the normal performance limits. The power available to the at least one motor may be reduced under the adjusted performance limits in proportion to the difference between the quantity of bateries mounted to the batery mounts and the normal batery quantity threshold.

[0015] The power available to the at least one traction motor within the adjusted performance limits may be less than the power available to the at least one traction motor within the normal performance limits. Thus, an excavator speed across the terrain may be less within the adjusted performance limits than within the normal performance limits. lire excavator may comprise a mam body rotatably mounted to an undercarriage by a swing system. The at least one motor may comprise at least one swing motor for rotating the main body. The power available to the at least one swing motor within the adjusted performance limits may be less than the power available to the at least one swing motor within the normal performance limits. Thus, a swung speed of tire main body about the undercarriage is less within the adjusted performance limits than within the normal performance limits. lire excavator may comprise an arm arrangement controlled by a hydraulic system. The hydraulic system may comprise at least one hydraulic pump and / or hydraulic valve for controlling an extension and / or orientation of the arm arrangement. The at least one motor may comprise at least one pump motor for driving the at least one hydraulic pump. The power available to the at least one pump motor within the adjusted performance limits may be less than the power available to the at least one pump motor within the normal performance limits. A pump power in the hydraulic system for controlling the arm arrangement may be less within the adjusted performance limits than within the normal performance limits.

[0016] The electrical power system may further comprise at least one auxiliary system. The power available to the at least one auxiliary’ system within the adjusted performance limits is less than the power available to the at least one auxiliary system within the normal performance limits.

[0017] The electrical power sy stem may further comprise at least one tether port for connection to an external power supply for supplying power to the at least one motor. The machine control system may be configured to simultaneously supply power to the at least one motor from the at least one tether port and from at least one batery' mounted to the battery mounts. The machine control system may be further configured to operate the electrical power sy stem in accordance with the normal performance limits if the quantity of batteries mounted to the battery mounts is less than the normal battery quantity threshold by receiving power from the at least one tether port. Tire machine control system may be further configured to operate the electrical power system in accordance with the normal performance limits if the quantity of batteries mounted to the battery mounts is less than the normal battery’ quantity threshold by simultaneously supplying power to the at least one motor from the external power supply and from at least one battery' mounted to the battery mounts.

[0018] ITe machine control system may comprise a user interface for receiving an input from an operator. The machine control system may’ be configured to operate the electrical power system in accordance with the normal performance limits if the quantity of batteries mounted to the batery' mounts is less than the normal batery quantity threshold upon receipt of an override input at the user interface. The machine control system may be configured to receive an input at the user interface from an operator to determine the battery capacity mounted to the batery' mounts. The user interface may be configured to display to the operator that the machine control system is operating under the adjusted performance limits. The user interface may' be configured to display' the quantity’ of batteries to the operator.

[0019] The machine control system may be configured to operate the excavator within a plurality of different adjusted performance limits. Each different adjusted performance limit may affect the runtime available to the excavator based upon the quantity of bateries mounted to the battery' mounts. The machine control system may' be configured to select one of the different adjusted performance limits in response to an input at the user interface by the operator.

[0020] ITe machine control system may be configured to operate the excavator within the adjusted performance limits to account forthe adjusted stability ofthe excavator due to the quantity of bateries mounted to the battery' mounts being less than the normal batery quantity threshold.

[0021] At least one counterweight pack may be mounted to at least one of the battery’ mounts. The machine control system may' be configured to operate the excavator within the adjusted performance limits to adjust the stability of the excavator to account for the quantity of batteries and counterweight packs mounted to the battery mounts being less than the normal battery quantity threshold. Within the adjusted performance limits the maximum speed and / or torque of the at least one swing motor may be reduced to account for the quantity of bateries mounted to the battery' mounts being less than the normal battery' quantity threshold.

[0022] The arm arrangement may be operable within a normal extension envelope under the normal performance limits and within a restricted extension envelope under the adjusted performance limits. The maximum extension of the arm arrangement may be less in the restricted extension envelope than in the normal extension envelope.

[0023] Within the adjusted performance limits the hydraulic system may be operated to reduce the maximum speed of movement of the arm arrangement, and / or to reduce the maximum pressure available to move the arm arrangement, to account for the quantity of batteries mounted to the battery' mounts being less than the normal battery' quantity threshold.

[0024] The user interface may be configured to display to the operator a normal extension envelope under the normal performance limits and a restricted extension envelope under the adjusted performance limits. The maximum extension of the arm arrangement may be less m the restricted extension envelope than in the nonnal extension envelope.

[0025] Tire present disclosure further provides, alternatively or additionally, an excavator comprising an arm arrangement and an electrical power system. The electrical power system comprises at least one motor for driving the excavator across a terrain; at least one battery; and optionally at least one battery interface releasably connectable to the battery’ and electrically connected to the at least one motor for supplying power thereto. Tire excavator further comprises at least one battery- mount configured to receive the at least one battery optionally such the at least one battery is connectable to the battery interface. At least one counterweight pack is mounted to the at least one battery' mount. The at least one counterweight pack is configured to counterbalance the arm arrangement at least partially. The at least one batery may or may not be mounted to the at least one battery mount and when mounted, the at least one batery and at least one counterweight pack are configured to counterbalance the arm arrangement at least partially.

[0026] Each battery mount may comprise a mount engager. The at least one counterweight pack may comprise a counterweight engager for engaging with the mount engager. The at least one battery may comprise a battery engager for engaging with the mount engager. A mount fastener may be connectable between the counterweight engager and battery mount and connectable between the battery engager and battery mount.

[0027] The weight and / or shape of the or each at least one counterweight pack may be substantially the same as the weight and / or shape respectively of the or each at least one batery . The at least one battery may comprise at least one battery and / or fuel cell pack comprising at least one battery and / or fuel cell respectively.

[0028] The electrical power system may be connectable, in a tethered configuration, to a power supply external to the excavator for supplying power to the electrical power system by at least one external power supply cable. In the tethered configuration the electrical power system may be operable to drive the system across the terrain with or without at least one battery’ mounted to at least one battery mount and / or with at least one counterweight pack mounted to at least one baiicn. mount.

[0029] The excavator may comprise a main body rotatably mounted to an undercarriage, wherein the at least one battery mount is located in a counterweight section of the main body. The excavator may comprise a control system configured to determine whether at least one batery and / or at least one counterweight pack is mounted to the at least one battery mount.

[0030] The present disclosure further provides, alternatively or additionally, a method of operating the aforementioned excavator. The method may comprise replacing at least one batery mounted to at least one batten- mount with at least one counterweight pack mounted to at least one of the at least one batery mount to counterbalance the arm arrangement at least partially.

[0031] Brief Description of the Drawings

[0032] By way of example only, embodiments of the present disclosure are now' described with reference to, and as shown in, the accompanying drawings, in which:

[0033] Figure 1 is a schematic perspective view of an excavator in accordance with the present disclosure;

[0034] Figure 2 is a schematic top plan view' of the excavator of Figure 1 ; and

[0035] Figure 3 is a schematic view of a battery mounting arrangement of the excavator of Figure 1. Detailed Description

[0036] The ensuing description provides preferred exemplar}- 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 embodirnent(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.

[0037] 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.

[0038] 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.

[0039] 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. Tins 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.

[0040] Excavators are equipped with a counterweight at the rear end of the excavator to prevent the excavator tipping forward when the stick and / or boom at the front of the excavator are operated, such as when the stick and boom are extended forward from the excavator and engaged with the ground. Electric excavators may be powered by batteries, tethering to an electric power source, hybrid technologies (electric / diesel), etc. For electric excavators, different power arrangements may be desirable for different operating conditions. For example, for suburban operation or the like, where external power sources are available, tethering the excavator to an external power source may be the most efficient mode of operation. Whereas, for work on a remote site, battery or hybrid power operation may be required. Moreover, for a tethered electric excavator, batteries are often used to complement the tethered power supply and to reduce the need for large cabling harnesses running through the core of the excavator to transmit large currents from the external supply, which can be inefficient. In some embodiments of this disclosure, the counterweight, at least in part, comprises a power bank comprising a plurality of batteries, where the batteries can be removably positioned at set locations in the power bank. By making the batteries removeable, it is possible to adjust the electrical power of the power bank. For example, if the excavator is scheduled to work in a tethered operation, batteries may be removed from the power bank. However, this removal of batteries may change the effectiveness of the counterweight, and so, in embodiments of the present disclosure, the battery’ locations receive counterweight packs equivalent to the removed battery' to maintain the excavator’s balance. The flexibility of the power bank provides that: the excavator may be set up in the most power efficient arrangement for its intended operation, the excavator can be setup to operate in different modes, i. e. , tethered mode, untethered mode, tethered mode with assist from batteries.

[0041] Figure 1 illustrates an embodiment of an excavator 10, which is a work machine for excavating material from the ground, terrain and / or worksite, according to the present disclosure. The excavator 10 may comprise a mam body 12 having a cab 8 for an operator and an arm arrangement 14 attached to the main body 12. The main body 12 may comprise a counterweight section 9 extending from the cab 8 on the opposite side thereof to the aim arrangement 14.

[0042] The excavator 10 may comprise a tool 15 connected to the arm arrangement 14 via a coupling arrangement 11. The arm arrangement 14 may comprise a boom 16, a stick 17 and a linkage arrangement 20 pivotally attached to one another. The coupling arrangement 11 may be mounted to the stick 17 and linkage arrangement 20. The arm arrangement 14 may’ comprise hydraulic actuators 18, 19, 21 for controlling the orientation and movement of the boom 16, stick 17 and linkage arrangement 20 and thereby the orientation and movement of the coupling arrangement 1 1 and tool 15.

[0043] The tool 15 may be of any suitable type and may, for example, be a grapple as illustrated or may be a bucket, tiltable bucket, tilt rotator, hammer, handling arm, multi-processor, pulveriser, saw, shears, blower, grinder, tiller, trencher, winch, auger, broom, cutter, planer, delimber, felling head, mulcher, or rake.

[0044] The excavator 10 may comprise an undercarriage 30 to which the main body’ 12 is rotatably mounted, such as via a swing system 31. The undercam age 30 may’ comprise a chassis 32 to which at least one wheel and / or track 13 may be mounted for driving the excavator 10 along a terrain 33. The swing system 31 may be mounted to a top of the chassis 32 and the at least one wheel and / or track 13 may be mounted to opposing sides of the chassis 32. The swing system 31 may comprise at least one swing motor 70 for rotating the main body 12 relative to the undercarriage 30.

[0045] The excavator 10 may comprise a hydraulic system 5 for operating the arm arrangement 14 and / or at least one tool 15 and around which fluid may be circulated. Idle excavator 10 may comprise a machine control system 90 (discussed further below) for controlling the hydraulic system 5 automatically or based upon inputs received from a user interface 6. Tire user interface may comprise an input device controllable by an operator in the main body 12, such as a joystick or at least one button, and may comprise at least one display for displaying information to a user, such as a screen or lighting.

[0046] The hydraulic system 5 may comprise a hydraulic reservoir 25, at least one hydraulic pump 26, at least one hydraulic valve (not illustrated) and / or hydraulic hoses 27. The hydraulic system 5 may comprise at least one hydraulic pump 26 and / or hydraulic valve for controlling an extension and / or orientation of the arm arrangement 14. The hydraulic system 5 may comprise the first, second and third hydraulic actuators 18, 19, 21 for controlling the pivoting of the arm arrangement 14 and the tool 15. The hydraulic system 5 may also comprise at least one conduit leading to or away from the at least one coupling arrangement 11 for communicating fluid to or from the at least one coupling arrangement 1 1 and tool 15.

[0047] Tire excavator 10 comprises an electrical power system 40, illustrated further in Figure 3, comprising at least one motor 71, which may comprise at least one traction motor 41 for driving the excavator 10 across the terrain 33. The electrical power system 40 may be distributed across the excavator 10 between the mam body 12 and undercarriage 30. The at least one traction motor 41 may be mounted in the undercarriage 30 and connected directly or indirectly to the at least one wheel and / or track 13.

[0048] Tire at least one motor 71 may comprise at least one pump motor 72 configured to drive the at least one hydraulic pump 26. The at least one motor 71 may comprise the at least one swing motor 70. Tire at least one traction motor 41 , pump motor 72 and / or swing motor 70 may be separate motors or may be the same at least one motor 71 configured to drive the excavator 10 across the terrain 33, drive the at least one hydraulic pump 26 and / or rotate the main body 12 relative to the undercarnage 30, The electrical power system 40 may comprise at least one auxiliary system 73. The auxiliary system 73 may comprise any suitable auxiliary component requiring power, such as main lights, lights in the cab 8, the user interface 6 and the like.

[0049] The electrical power system 40 comprises at least one batery 45 for supplying electrical power to the electrical power system 40, in particular for driving the at least one motor 71, such as the at least one traction motor 41. The electrical power system 40 may comprise a plurality of such bateries 45.

[0050] Each battery 45 may comprise at least one batten' cell mounted within a pack housing 47. The at least one battery 46 may comprise a handle 48 mounted on the pack housing 47 for an operator to carry the at least one battery 46, for example when installing and removing the battery 46 on and from the excavator 10.

[0051] The or each batery' 45 may comprise a batery management system 49, which monitors and / or controls the battery 45. The batery management system 49 may comprise a battery controller, which may comprise a battery memory, which may store instructions or algorithms in the form of data, and a batten- processing unit, which may be configured to perform operations based upon the instructions. The battery controller may be of any suitable known type, lire battery memory 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 batery processing unit may comprise any suitable processor capable of executing memory-stored instructions, such as a microprocessor, uniprocessor, a multiprocessor and the like.

[0052] The electrical power system 40 comprises at least one baten- interface 50 releasably connectable to the at least one battery 45 and electrically connected to the at least one motor 71 for supplying power thereto from the battery 45. The electrical power system 40 may comprise a plurality of battery- interfaces 50, each battery- interface 50 being for connection to separate electrical power sources 45 or batteries. The or each batery interface 50 may comprise a socket to which the battery- 45 can be manually releasably connected.

[0053] The electrical power system 40 comprises at least one tether port 55 for connection to an external power supply 74. The at least one tether port 55 may- enable charging of the battery 45 from the external power supply 74 via the battery- interface 50. The at least one tether port 55 may be for supplying power to the electrical power system 40 for supplying power to the at least one motor 71.

[0054] The excavator comprises at least one battery mount 63. Each batten' mount 63 is configured to receive at least one battery 45 for supply power to the at least one motor 71. Each batery mount 63 may be configured to receive at least one battery 45 such the at least one battery 45 is connectable to the battery interface 50.

[0055] In particular, the excavator 10 may comprise a battery mounting arrangement 60 comprising a compartment 61 for receiving the batery' 45. The at least one battery mount 63 may be within the compartment 61 . Each battery mount 63 may comprise a single chamber in the compartment 61 as illustrated. Each chamber may be configured to receive one batter or a plurality of batteries 45, such as a single battery' 46 per chamber. The or each battery' interface 50 may be mounted within the compartment 61 and the or each battery- interface 50 may be mounted within or at each battery mount 63. lire at least one battery 45 may be connected to the at least one battery interface 50 during installation.

[0056] The batery' housing 60 may be mounted in the main body 12 as illustrated in Figures 1 and 2 and may, in particular, be mounted in the counterweight section 9. The counterweight section 9 may- be the portion of the main body' 12 on the other side, to the arm arrangement 14, of the centre of rotation of the main body 12 relative to the undercarriage 30 about the swing system 31. Thus, when at least one batery 45 is mounted in the pack housing 60, the at least one battery 45 may act to counterbalance the weight of at least the arm arrangement 14, optionally also the tool 15, anything being carried by the tool 15 and at least part of the main body- 12, across the swing system 31 .

[0057] At least one counterweight pack 80 may be mounted in at least one batterymount 63. The at least one counterweight pack 80 is for use or mounting in place of at least one battery 45 so as to counterbalance the weight of the arm arrangement 14 and anything being earned by the tool 15. The at least one counterweight pack 80 may' comprise a mass of material with no storing or provision of electrical energy and no ability to connect or supply electrical energy to the at least one batery interface 50. Hence the only functionality of at least one battery 45 achieved by the at least one counterweight pack 80 is that of providing a counterweight during operation of the excavator 10.

[0058] The weight and / or shape of the or each at least one counterweight pack 80 may be substantially the same as the weight and / or shape respectively of the or each at least one battery 45. As a result, the or each counterweight pack 80 fits within and / or mounts to each battery mount in the same manner as the or each battery 45. They can be swapped for one another when necessary. Along with each battery 45, each counterweight pack 80 may have the ability to be moved into position by a crane.

[0059] Each battery mount 63 may comprises a mount engager, such as a fixing for a bolt or other quick release fitting. The at least one counterweight pack 80 may comprise a counterweight engager for engaging with the mount engager. The at least one battery 45 may comprise a battery' engager for engaging with the mount engager. A mount fastener may be connectable between the counterweight engager and battery mount and connectable between the battery engager and battery mount, 'the battery and mount engagers may be substantially the same, such that they can interchangeably engage the mount engager, with or without the mount fastener. The mount fastener may be a bolt and nut and the battery, counterweight and mount engagers may comprise passages to receive the bolt and nut.

[0060] The excavator 10 may comprise a machine control system 90. The machine control system 90, may be configured to perform the methods of the present disclosure. The machine control system 90 may comprise a machine controller, which may comprise a machine memory, which may store instructions or algorithms in the form of data, and a machine processing unit, which may be configured to perform operations based upon the instructions. The machine controller may be of any suitable known type and may comprise an engine control unit (ECU) or the like. The machine memory 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 machine processing unit may comprise any suitable processor capable of executing memory-stored instructions, such as a microprocessor, uniprocessor, a multiprocessor and the like. The machine controller may further comprise a graphics processing unit for rendering objects for viewing on the display of the machine control system. The machine controller may also be in communication with an external computing system via a wired or wireless network (such as Ethernet, fibre optic, satellite communication network, broadband communication network, cellular, Bluetooth). The external computing system may comprise computing systems, processors, servers, memories, databases, control systems and the like. The machine control system 90 may be communicatively connected (via a wired or wireless connection) to the electrical power system 40 and hydraulic system 5 for providing control signals thereto and receiving sensor signals therefrom in order to control the operation of the excavator 10. The machine control system 90 may communicate with the user interface 6, for receiving an input and controlling the excavator 10 and for displaying information to the operator.

[0061] The machine control system 90 may comprise the necessary power electronics to control the power exchanged and / or regulate the electrical energy exchanged between the at least one batter 45, at least one tether port 55 and at least one motor 71 . In particular, the machine control system 90 may comprise a motor controller unit, at least one inverter, at least one sensor and / or any other suitable power electronics. The machine control system 90 may control the frequency, current and / or voltage of the electrical power in the electrical power system 40.

[0062] The machine control system 90 may be configured to determine the quantity (i.e., number) of batteries 45 mounted to the battery mounts 63. The battery' mounts 63 may only be capable of storing a maximum quantity of batteries 45, such as by there only being a certain number of batteries 45 mountable on the batten,' mounts 63. The machine control system 90 may store a normal battery' quantity threshold, which may be the normal number of batteries 45 required to be mounted to the battery' mounts 63 for the excavator to operate within normal performance limits (as discussed further below). The normal battery quantity threshold may be the maximum quantity of bateries 45 mountable to the battery mounts 63. Alternatively, the normal battery' quantity threshold may be less than the maximum quantity' of batteries 45, such as if redundancy is provided for in the maximum number of batteries 45 mounted.

[0063] The machine control system 90 may be configured to determine the quantity of batteries 45 mounted to the battery' mounts 63 by determining whether at least one battery-' 45 and / or at least one counterweight pack 80 is mounted to the or each battery' mount 63. In particular, the machine control system 90 may communicate with the battery' management system 49 when the battery 45 is connected to the battery interface 50. The battery controller and machine controller may be configured to communicate with one another. The machine controller may' be configured to interrogate the battery' controller, and / or receive a verification signal from the battery controller, to identify the battery'. Such verification may occur during a start-up sequence and / or periodically throughout use. The verification signal may be a heartbeat message as to whether the battery is or is not connected.

[0064] The machine control system 90 may be configured to determine whether at least one batery 45 is mounted to a battery' mount 63 by interrogating the batery management system 49. From such interrogation the machine control system 90 can determine information as to the installed energy, state of charge, state of health related to each battery-' 45. If no verification signal is received, the machine control system 90 may' determine that no battery 45 is present and / or that a counterweight pack is mounted to a battery mount 63 instead. If a verification signal is received, the machine control system 90 may determine that a battery 45 is mounted to the battery' mount 63.

[0065] Alternatively, the machine control system 90 may be configured to determine whether at least one battery' 45 and / or at least one counterweight pack 80 is mounted to the at least one battery mount 63 by receiving an input from an operator at the user interface 6. In particular, the operator may be able to indicate the configuration of battery(s) 45 and / or counterweight pack(s) 80 present via the user interface 6.

[0066] The machine control system 90 may alternatively be configured to determine whether at least one battery 45 and / or at least one counterweight pack 80 is mounted to the at least one battery' mount 63 by receiving the configuration of battery(s) 45 and / or counterweight pack(s) 80 present from the external computing system.

[0067] The machine control system 90 may be configured to operate the excavator 10 within normal performance limits if the quantity of batteries 45 mounted to the battery' mounts 63 is at least the normal battery quantity threshold and to operate the excavator 10 within adjusted performance limits if the quantity of batteries 45 mounted to the battery mounts 63 is less than the normal batery' quantity threshold. In effect, the machine control system 90 may operate the excavator 10 at its intended performance levels (i.e., normal performance limits) but, if the number of batteries installed is less that the full complement of batteries, the machine control system 90 may reduce performance of the excavator 10, or at least provide the operator with the option to operate at a reduced performance.

[0068] In summary, the machine control system 90 may adjust the performance limits by (a) adjusting the power available in the electrical power system 40, such as for the at least one motor 71, to account for the reduced power available from the batteries 45, (b) adjusting the stability of the excavator 10 to account for there potentially being less counterweight on the battery mounts 63 by having a reduced number of batteries 45, and / or (c) provide information to and receive input(s) from an operator via the user interface 6 to allow the operator to determine how the machine control system 90 should adjust the performance limits in the view' of the reduced quantity of batteries 45.

[0069] The machine control system 90 may control the power transferred by the electrical power system 40 to the at least one motor 71 within the normal, or adjusted, performance limits. In particular, the machine control system 90 may control the power transferred to the at least one motor 71 from the at least one batten' 45 mounted to at least one of the battery mounts 63 and / or from the at least one tether port 55.

[0070] When operating within the adjusted performance limits, the machine control system 90 may control the electrical power system 40 such that the power available to the at least one motor 71 is less than the power available to the at least one motor 71 when operating within the normal performance limits. Hence the machine control system 90 may restrict the power supplied to the at least one motor 71 if the quantity of batteries 45 mounted to the battery' mounts 63 is less than the normal battery quantity threshold.

[0071] When operating within the adjusted performance limits, the machine control system 90 may reduce tire power available to the at least one motor 71 in proportion to the difference between the quantity of batteries 45 mounted to the battery mounts 63 and the normal batery quantity threshold. Hence, for example, if the quantity of batteries 45 mounted to the battery' mounts 63 is 25% less than the normal battery' quantity threshold, the power available may be reduced by 25%.

[0072] When operating within the adjusted performance limits, the machine control system 90 may adjust the power available to the at least one traction motor 41 , swing motor 70, pump motor 72 and / or auxiliary' system 73 to be less than the power available to the at least one traction motor 41, swing motor 70, pump motor 72 and / or auxiliary system 73 when operated by the machine control system 90 within the normal performance limits,

[0073] Tire maximum power available to the at least one traction motor 41 , swing motor 70, pump motor 72 and / or auxiliary- system 73 may be reduced. Therefore, a maximum excavator 10 speed across the terrain may be less within the adjusted performance limits than within the normal performance limits. A maximum swing speed of the main body 12 about the undercarriage 30 may be less within the adjusted performance limits than within the normal performance limits. A maximum pump pow'er in the hydraulic system 5 for controlling the arm arrangement 14 is less within the adjusted performance limits than within the normal performance limits. Operation of the auxiliary system 73 at maximum power may also be reduced, such as by preventing multiple systems being operated at the same time (e.g., preventing the ability to switch on main lights or the like).

[0074] The average power available to the at least one traction motor 41, swing motor 70, pump motor 72 and / or auxiliary system 73 over a predetermined time period may be reduced. Therefore, short periods of high power operation may be available, provided that they are preceded or followed by periods of low' power operation within the predetermined time period.

[0075] The machine control system 90 may also account for whether power is being received from the external power supply 74 via the at least one tether port 55 when adjusting the performance of the excavator 10 to account for having fewer batteries 45 than the normal battery' quantity threshold. In particular, the machine control system 90 may be configured to supply power to the at least one motor 71 from the at least one tether port 55 and, optionally, simultaneously from at least one batery 45 mounted to the battery mounts 63. The at least one tether port 55 may be configured to receive such power from the external power supply 74. If any batteries 45 are mounted to the battery' mounts 63, the machine control system 90 may receive power therefrom to supplement power from the at least one tether port 55 or vice-versa.

[0076] If the excavator 10 is tethered to the external power supply 74 then it may be operational in accordance with the normal performance limits, even if the quantity of batteries 45 mounted to the battery mounts 63 is less than the normal battery-' quantity' threshold. Therefore, the machine control system 90 may be further configured to operate the electrical power system 40 in accordance with the normal performance limits if the quantity of batteries 45 mounted to the battery mounts 63 is less than the normal battery quantity' threshold by receiving power from the at least one tether port 55 and, optionally, simultaneously from at least one battery' 45 mounted to the battery' mounts 63. The total power supplied by the at least one tether port 55, optionally in addition to any power from any batteries 45 mounted to the battery' mounts 63, may be sufficient for the excavator 10 to operate normally.

[0077] As mentioned above, the machine control system 90 is also configured to operate the excavator 90 within the adjusted performance limits to account for the adjusted stability of the excavator 10 due to the quantity of batteries 45 mounted to the battery mounts being less than the normal battery quantity threshold.

[0078] If the machine control system 90 determines that all battery’ mounts 63 have a battery' 45 or counterweight pack 80 mounted thereon then the machine control system 90 may not adjust the performance limits to adjust the stability of the excavator 10, since it will not have changed compared to there being a full complement of batteries 45.

[0079] The quantity of batteries 45 mounted to the battery' mounts 63 may’ also account for the number of counterweight packs 80 mounted to the battery- mounts. If at least one counterweight pack 80 is mounted to at least one of the battery mounts 63, the machine control system 90 may be configured to operate the excavator 10 within the adjusted performance limits to adjust the stability of the excavator 10 to account for the quantity of batteries 45 (which may be zero) and counterweight packs 80 mounted to the batery mounts 63 being less than the normal battery quantity threshold.

[0080] The machine control system 90 may adjust the performance limits in any way suitable to ensure that the excavator 10 remains stable and, for example, is at low risk of toppling over.

[0081] When operating within the adjusted performance limits, the machine control system 90 may’ reduce the speed and / or torque, preferably the maximum speed and / or torque, of the at least one traction and / or swing motor 41, 70 to account for the quantity of batteries 45 and / or counterweight packs 80 mounted to the battery' mounts 63 being less than the normal battery quantity threshold. Therefore, the momentum of the excavator 10, main body 12. and / or arm arrangement 14 may be reduced, improving the stability of the excavator 10 and reducing the risk of topple over.

[0082] When operating within the normal performance limits, the machine control system 90 may operate the arm arrangement 14 and / or tool 15 within a normal extension envelope. The extension envelop may define the maximum outer extension of the arm arrangement 14 and / or tool 15 allowed and may' be at a maximum in the normal extension envelop. When operating wdthin the adjusted performance limits, the machine control system 90 may operate the arm arrangement 14 and / or tool 15 within an adjusted extension envelope, "fire maximum extension of the arm arrangement 14 and / or tool 15 may be less in the restricted extension envelope than in the normal extension envelope. Therefore, the machine control system 90 can ensure that the arm arrangement 14 and / or tool 15 cannot overextend and increase the risk of topple over when there are fewer batteries 45 and / or counterweight packs 80 than the normal battery quantity threshold.

[0083] When operating within the adjusted performance limits, the machine control system 90 may operate the hydraulic system 5 to reduce the maximum speed of movement of the arm arrangement 14 and / or tool 15, and / or to reduce the maximum pressure available to move the arm arrangement 14 and / or tool 15, to account for the quantity of batteries 45 and / or counterweight packs 80 mounted to the battery mounts 63 being less than the normal battery' quantity threshold.

[0084] The machine control system 90 may also be configured to receive input from an operator via the user interface 6 and to display information to the operator via the user interface 6 when determining whether to operate the excavator within the normal or adjusted performance limits. In particular, the operator may be able to override the implementation of the adjusted performance limits if there are sufficient bateries 45 present to maintain operation at the normal performance limits, albeit for a shorter period of time.

[0085] Therefore, the machine control system 90 may be configured to operate the electrical power system 40 in accordance with the normal performance limits if the quantity of batteries 45 mounted to the battery mounts 63 is less than the normal battery' quantity threshold upon receipt of an override input at the user interface 6.

[0086] Tire user interface 6 may be configured to display to the operator that the machine control system 90 is operating under the adjusted performance limits and may provide the operator with the opportunity to override such operation. The user interface 6 may be configured to display the quantity of batteries 45 present to the operator.

[0087] The machine control system 90 may configure the user interface 6 to display to the operator the normal extension envelope under the normal performance limits and to display to the operator the restricted extension envelope under the adjusted performance limits. Such a display may be in addition to or alternatively to the machine control system 90 restricting operation to the restricted extension envelope - i ,e., such that either the restricted extension envelope is implemented by control and / or by allowing the operator to control operation fully but displaying the restricted extension envelope to them.

[0088] The operator may be able to select different performance limits for the machine control system 90 to implement based upon an expected runtime at the different performance limits, particularly if operating without power being received at the at least one tether port 55. Therefore, the operator can choose between higher powered, lower runtime performance limits and lower powered, longer runtime performance limits.

[0089] The machine control system 90 may be configured to operate the excavator 10 within a plurality of different adjusted performance limits. Each different adjusted performance limit may comprise a different adjusted power level available to the at least one motor 71, the adjusted power levels being less than tire power available to the at least one motor 71 when operating within the normal performance limits. Thus, by' having different power levels available, each different adjusted performance limit will have a different runtime before the energy available in the batteries 45 has depleted.

[0090] The plurality' of different adjusted performance limits may be displayed to the operator via the user interface 6. The operator can provide an input to the user interface 6 to select one of the different adjusted performance limits according to the suitable runtime and adjusted power level for the work they need to perform with the excavator 10.

[0091] Industrial Appli cability

[0092] The batteries 45 may require removal for maintenance or for recharging. Alternatively, sufficient fully charged batteries 45 may not be available to fill or be mounted to every' batery' mount 63. However, if bateries 45 are not present on every' battery mount 63, the excavator 10 may not be able to operate correctly, such as because it may be unbalanced by the lack of counterweight effect from the bateries 45 and / or because it has insufficient power available to operate at its normal performance limits.

[0093] Therefore, in order to maintain stable operation of the excavator, at least one battery' 45 mounted to at least one battery mount 63 may be replaced with at least one counterweight pack 80. The at least one counterweight pack 80 may' provide the necessary’ counterbalance to the arm arrangement 14 and anything being carried by the tool 15 such that the excavator 10 can operate effectively, as if at least one batery' 45 was mounted to each at least one battery mount 63.

[0094] If there are insufficient counterweight packs 80 and / or batteries 45 mounted to the batery' mounts 63 to reach the normal batter quantity threshold, the machine control system 90 operates the excavator 90 within the adjusted performance limits to account for the adjusted stability of the excavator 10. In particular, the machine control system 90 may limit the speed of movement of the excavator 10, the swing system 31, the arm arrangement 14 and / or the tool 15 to reduce the momentum of movement and thus improve stability.

[0095] If batteries 45 are missing, the machine control system 90 can implement an adjusted perfonnance limits to restrict power available to the at least one traction motor 41, swing motor 70, pump motor 72 and / or auxiliary system 73. Therefore, the excavator 10 can still operate to some extent even without a full complement of batteries. However, the maximum power and / or runtime in the electrical power system 40 may be reduced.

[0096] The operator may be able to implement different adjusted performance limits to obtain a desired runtime and / or power output, or to override the implementation of the adjusted performance limits such that the excavator 10 operates according to normal perfonnance limits. In this way, the operator has the flexibility to operate the excavator 10 if they determine that they have sufficient batery capacity to perform the work they need to do.

[0097] In addition, the excavator 10 can operate in a tethered configuration without any batteries 45 mounted therein, or with only some batteries 45 mounted therein. The electrical power system 40 may be connectable, in the tethered configuration, to a power supply external to the excavator 10 for supplying power to the electrical power system 40 by at least one external power supply cable.

[0098] When tethered and receiving sufficient power from the external power supply 74 and / or any installed batteries 45, the excavator 10 may then be operable according to its normal performance limits. For example, if the electrical power system 40 requires 100k W to operate under normal performance limits, but the external power supply 74 can only provide 75kW, the machine control system 90 may direct power from 25kW batery 45 capacity mounted to the batery mounts 63 such that normal performance limits can be implemented.

[0099] In the tethered configuration the electrical power system 40 is operable to drive the excavator 10 and / or operate the at least one arm arrangement 14 and / or tool 15 with or without at least one batery 45 mounted to at least one battery mount 63 and / or with at least one counterweight pack 80 mounted to at least one battery mount 63.

[0100] By virtue of the or each at least one battery mount 63 having a battery 45 and / or counterweight pack 80 mounted thereon, the excavator 10 can operate in the tethered configuration at full effectiveness, with the arm arrangement 14 and anything being carried by the tool 15 being correctly counterbalanced.

Claims

Claims1 . An excavator comprising: an electrical power system comprising at least one motor for operating the excavator; battery’ mounts, each battery mount being configured to receive at least one battery’ for supplying power to the at least one motor; and a machine control system configmed to: determine the quantity of batteries mounted to the battery mounts; operate the excavator within normal performance limits if the quantity of batteries mounted to the battery- mounts is at least a normal battery- quantity threshold; and operate the excavator within adjusted performance limits if the quantity of batteries mounted to the battery mounts is less than the normal battery quantity threshold.

2. An excavator as claimed in claim 1 wherein the machine control system is configured to control the power transferred by the electrical power system to the at least one motor within the normal, or adjusted, performance limits,3. An excavator as claimed in any one of the preceding claims wherein the machine control system controls the electrical power system such that the power available to the at least one motor within the adjusted performance limits is less than the power available to the at least one motor within the normal performance limits.

4. An excavator as claimed in any one of the preceding claims wherein the at least one motor comprises at least one traction motor for driving the excavator across a terrain, wherein the power available to the at least one traction m otor within the adj usted performance limits is less than the power available to the at least one traction motor within the normal performance limits such that an excavator speed across the terrain is less within the adjusted performance limits than within the normal performance limits.

5. An excavator as claimed in any one of the preceding claims wherein: the excavator comprises a main body rotatably mounted to an undercarriage by a swing system;the at least one motor comprises at least one swing motor for rotating the main body; and the power available to the at least one swing motor within the adjusted performance limits is less than the power available to the at least one swing motor within the normal performance limits such that a swing speed of the main body about the undercarriage is less within the adjusted performance limits than within the normal performance limits.

6. An excavator as claimed in any one of the preceding claims wherein: the excavator comprises an arm arrangement controlled by a hydraulic system, the hydraulic system comprising at least one hydraulic pump and / or hydraulic valve for controlling an extension and / or orientation of the arm arrangement; the at least one motor comprises at least one pump motor for driving the at least one hydraulic pump; and the power available to the at least one pump motor within the adjusted performance limits is less than the power available to the at least one pump motor within the normal performance limits such that a pump power in the hydraulic system for controlling the arm arrangement is less within the adjusted performance limits than within the normal performance limits.

7. An excavator as claimed in any one of the preceding claims wherein the electrical power system further comprises at least one auxiliary system, wherein the power available to the at least one auxiliary system within the adjusted performance limits is less than the power available to the at least one auxiliary system within the normal performance limits.

8. An excavator as claimed in any one of the preceding claims wherein the electrical power system further comprises at least one tether port for connection to an external power supply for supplying power to the at least one motor, further w'herein the machine control system is configured to: simultaneously supply power to the at least one motor from the at least one tether port and from at least one batten’ mounted to the battery' mounts;operate the electrical power system in accordance with the normal performance limits if the quantity of batteries mounted to the battery mounts is less than the normal battery' quantity threshold by receiving power from the at least one tether port; and / or operate the electrical power system in accordance with the normal performance limits if the quantity of batteries mounted to the battery mounts is less than the normal battery’ quantity threshold by simultaneously supplying power to the at least one motor from the external power supply and from at least one battery' mounted to the battery mounts.

9. An excavator as claimed in any one of the preceding claims wherein the machine control system comprises a user interface for receiving an input from an operator, further wherein: the machine control system is further configured to operate the electrical power system in accordance with the normal performance limits if the quantity of batteries mounted to the battery mounts is less than the normal battery quantity threshold upon receipt of an override input at tire user interface; the machine control system is configured to receive an input at the user interface from an operator to determine the battery' capacity mounted to the battery' mounts; the machine control system is configured to operate the excavator within a plurality of different adjusted performance limits, each different adjusted performance limit affecting the runtime available to the excavator based upon the quantity of batteries mounted to the battery mounts, wherein the machine control system is configured to select one of the different adjusted performance limits in response to an input at the user interface by the operator; and / or the user interface is configured to display to the operator a normal extension envelope under the normal performance limits and a restricted extension envelope under the adjusted performance limits, the maximum extension of the arm arrangement being less in the restricted extension envelope than in the normal extension envelope.

10. An excavator as claimed in any one of the preceding claims wherein the machine control system is configured to operate the excavator within the adjustedperformance limits to account for the adjusted stability of the excavator due to the quantity of batteries mounted to the batten-’ mounts being less than the normal battery' quantity threshold.

11. An excavator as claimed in claim 10 wherein at least one counterweight pack is mounted to at least one of the battery mounts and the machine control system is configured to operate the excavator within the adjusted performance limits to adjust the stability of the excavator to account tor the quantity of batteries and counterweight packs mounted to the battery mounts being less than the normal battery quantity threshold.

12. An excavator as claimed in claim 10 or claim 1 1 wherein within the adjusted performance limits the maximum speed and / or torque of the at least one swing motor is reduced to account for the quantity of batteries mounted to the battery mounts being less than the normal battery' quantity threshold.

13. An excavator as claimed in any one of claims 10 to 12. wherein the arm arrangement is operable within a normal extension envelope under the normal performance limits and within a restricted extension envelope under the adjusted performance limits, the maximum extension of the arm arrangement being less in the restricted extension envelope than in the normal extension envelope.

14. An excavator as claimed in any one of claims 10 to 13 wherein within the adjusted performance limits the hydraulic system is operated to reduce the maximum speed of movement of the arm arrangement, and / or to reduce the maximum pressure available to move the arm arrangement, to account for the quantity of batteries mounted to the battery mounts being less than the normal battery’ quantity threshold.

15. A method of operating an excavator according to any one of the preceding claims, the method comprising, by the machine control system: determining the quantity’ of batteries mounted to the battery’ mounts;operating the excavator within normal performance limits if the quantity of batteries mounted to the battery mounts is at least a nonnal batten,' quantity threshold; and operating the excavator within adjusted performance limits if the quantity of batteries mounted to the battery mounts is less than the nonnal battery quantity threshold.

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