Excavator with loader control emulation

Abstract

An excavator (200) includes a controller (462) coupled to first and second operator input devices and a mode selection input. The controller (462) is configured to determine a selected mode of operation. When the selected mode of operation is a first mode of operation, a first set of machine functions is controlled by the operator's manipulation of the first and second operator input devices. When the selected mode of operation is a second mode of operation, a second set of machine functions is controlled by the operator's manipulation of the first and second operator input devices. The first set includes at least one machine function that is not a part of the second set. A first machine function is included in the first set and the second set. The first machine function is controlled using the second operator input device in both of the first and second modes of operation.

Description

EXCAVATOR WITH LOADER CONTROL EMULATIONBACKGROUND

[0001] This disclosure is directed toward power machines. More particularly, this disclosure is directed to excavators with lift arm structures. Power machines, for the purposes of this disclosure, include any type of machine that generates power to accomplish a particular task or a variety of tasks. One type of power machine is a work vehicle. Work vehicles are generally self- propelled vehicles that have a work device, such as a lift arm (although some work vehicles can have other work devices) that can be manipulated to perform a work function. Work vehicles include excavators, loaders, utility vehicles, tractors, and trenchers, to name a few examples.

[0002] Excavators are a known type of power machine that have an undercarriage and a house that selectively rotates on the undercarriage. A lift arm structure to which an implement can be attached is operably coupled to, and moveable under power with respect to, the house. Excavators are also typically self-propelled vehicles. Tracked excavators have endless tracks that rotate about track frames to propel the machine. These track frames are attached to an undercarriage of the excavator, often with the power system included in the upper machine portion or house of the excavator. The upper machine portion of the excavator pivots with respect to the undercarriage about a vertical axis on a swivel joint, which allows for rotational movement of the upper machine portion in either direction relative to the undercarriage.

[0003] While excavators provide the ability to perform a number of different work functions, it is often necessary to have different types of power machines at a job site in order to perform all necessary work functions. For example, it may be necessary to also have a loader, a telehandler, or other types of power machines available for loading or unloading materials or performing other work functions.

[0004] The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.SUMMARY

[0005] Disclosed are power machines such as excavators with control inputs that are configurable to control various functions on the excavator. In a traditional excavator mode,selected control inputs are manipulate to control the position of a lift arm structure, bucket, and house position. In an alternative mode to emulate a loader, the same control inputs are used to control tractive motion of the machine across a ground surface, level implement (workgroup) raising and lowering, and implement rolling.

[0006] In one aspect, an excavator comprises a frame and a first lift arm structure configured to be moved relative to the frame. The first lift arm structure comprises a boom portion and an arm portion, the arm portion configured to have a first implement mounted thereto by an implement interface. A controller is communicatively coupled to a first operator input device, a second operator input device and a mode selection input, wherein the controller is configured to determine a selected mode of operation, from at least two modes of operation, based upon an indication provided by the mode selection input, and to analyze inputs from the first operator input device and the second operator input device based upon the determined selected mode of operation to control machine functions, responsive to the operator's manipulation of the first operator input device and the second operator input device. When the selected mode of operation is a first mode of operation, a first set of machine functions is controlled by the operator's manipulation of the first operator input device and the second operator input device. When the selected mode of operation is a second mode of operation, a second set of machine functions is controlled by the operator's manipulation of the first operator input device and the second operator input device. The first set includes at least one machine function that is not a part of the machine functions in the second set. A first machine function (for example bucket dump / bucket curl and implement roll-in / implement roll-out) is included in each of the first set of machine functions and the second set of machine functions. In an exemplary embodiment, bucket dump / bucket curl and implement roll-in / implement roll-out are considered to be the same machine function in both the first and second modes; they are given different terminology because in the second mode, the implement may be a more conventional loader implement rather than a bucket. In an exemplary embodiment, the first machine function is controlled using the second operator input device in both the first mode of operation (FIG. 7A) and in the second mode of operation (FIG. 7B).

[0007] In another aspect, a method of selecting a mode of operation for first and second user input devices on an excavator and controlling the excavator is described. In an exemplaryembodiment, the excavator comprises a frame comprising an upper structure and a lower structure, a lift arm structure comprising a boom and an arm, and a plurality of actuators. In an exemplary embodiment, a first end of the boom is pivotally coupled to the frame, and a first end of the arm is pivotally coupled to a second end of the boom. In an exemplary embodiment, the lift arm structure is configured to have an implement coupled to a second end of the arm. An exemplary method comprises receiving a mode selection input from a mode selection input device and determining a selected mode of operation, from at least two modes of operation, based upon the mode selection input. An exemplary method comprises configuring a controller to analyze inputs from the first and second user input devices based upon the determined selected mode of operation and controlling machine functions, responsive to an operator's manipulation of the first and second user input devices, using the configured controller. An exemplary method comprises controlling the plurality of actuators using the first and second user inputs in a first mode of operation and a second mode of operation. In the first mode of operation, a first subset of the plurality of actuators is controlled to provide: a first function relating to a rotational position of the upper structure relative to the lower structure and a second function, responsive to the second user input device, relating to movement of the implement relative to the arm (such as bucket dump and bucket curl). In the second mode of operation, a second subset of the plurality of actuators is controlled to provide the second function, responsive to the second user input device, relating to movement of the implement relative to the arm (such as implement roll-in and implement roll-out), and third function relating to travel of the excavator.

[0008] This Summary and the Abstract are provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a block diagram illustrating functional systems of a representative power machine on which embodiments of the present disclosure can be practiced.

[0010] FIG. 2 is a front left perspective view of a representative power machine in the form of an excavator on which the disclosed embodiments can be practiced.

[0011] FIG. 3 is a rear right perspective view of the excavator of FIG. 2.

[0012] FIG. 4 is a side elevation view of the excavator in a first excavator mode.

[0013] FIG. 5 is a side elevation of the excavator in a second loader mode.

[0014] FIG. 6 is a block diagram illustrating portions of a control system of an excavator according to one illustrative embodiment.

[0015] FIG. 7A is a function map diagram illustrating the mapping of control functions to joystick controls in a first excavator mode according to one illustrative embodiment.

[0016] FIG. 7B is a function map diagram illustrating the mapping of control functions to joystick controls in a second loader mode according to one illustrative embodiment.

[0017] FIG. 8 is a flow diagram illustrating a method of controlling an excavator according to one illustrative embodiment.DETAILED DESCRIPTION

[0018] The concepts disclosed in this discussion are described and illustrated with reference to exemplary embodiments. These concepts, however, are not limited in their application to the details of construction and the arrangement of components in the illustrative embodiments and are capable of being practiced or being carried out in various other ways. The terminology in this document is used for description and should not be regarded as limiting. Words such as “including,” “comprising,” and “having” and variations thereof as used herein are meant to encompass the items listed thereafter, equivalents thereof, as well as additional items.

[0019] Disclosed embodiments illustrate an excavator and a control system for an excavator that provide for a plurality of modes of operation. The control system includes a pair of two-axis operator inputs and a mode select input. In a first mode of operation, the pair of two-axis operator inputs are mapped to control one set of functions on the implement. In a second mode of operation, the pair of multi-axis operator inputs are mapped to control a second set of functions on the implement.

[0020] These concepts can be practiced on various power machines, as will be described below. A representative power machine on which the embodiments can be practiced is illustrated in diagram form in FIG. 1 and one example of such a power machine is illustrated in FIG. 2-5. For the sake of brevity, only one power machine is discussed. However, the disclosed teachings can be practiced on any of a number of power machines, including power machines of differenttypes from the representative, illustrated power machine. Power machines, for the purposes of this discussion, include a frame, at least one work element, and a power source that can provide power to the work element to accomplish a work task. One type of power machine is a self- propelled work vehicle. Self-propelled work vehicles are a class of power machines that include a frame, work element, and a power source that can provide power to the work element. At least one of the work elements is a motive system for moving the power machine under power.

[0021] Referring now to FIG. 1, a block diagram illustrates the basic systems of a power machine 100 upon which the embodiments discussed below can be advantageously incorporated and can be any of several distinct types of power machines. The block diagram of FIG. 1 identifies various systems on power machine 100 and the relationship between various components and systems. As mentioned above, at the most basic level, power machines for the purposes of this discussion include a frame, a power source, and a work element. The power machine 100 has a frame 110, a power source 120, and a work element 130. Because power machine 100 shown in FIG. 1 is a self-propelled work vehicle, it also has tractive elements 140, which are themselves work elements provided to move the power machine over a support surface and an operator station 150 that provides an operating position for controlling the work elements of the power machine. A control system 160 is provided to interact with the other systems to perform various work tasks at least in part in response to control signals provided by an operator.

[0022] Certain work vehicles have work elements that can perform a dedicated task. For example, some work vehicles have a lift arm structure to which an implement 180 such as a bucket is attached such as by a pinning arrangement. The work element, i.e., the lift arm structure can be manipulated to position the implement 180 for performing the task. The implement 180, in some instances can be positioned relative to the work element, such as by rotating a bucket relative to a lift arm structure, to further position the implement. Under normal operation of such a work vehicle, the bucket is intended to be attached and under use. Such work vehicles may be able to accept other implements by disassembling the implement / work element combination and reassembling another implement in place of the original bucket. Other work vehicles, however, are intended to be used with a wide variety of implements and have an implement interface such as implement interface 170 shown in FIG. 1. At its most basic, implement interface 170 is a connection mechanism between the frame 110 or a work element130 and an implement 180, which can be as simple as a connection point for attaching an implement directly to the frame 110 or a work element 130 or more complex, as discussed below.

[0023] On some power machines, implement interface 170 can include an implement carrier, which is a physical structure movably attached to a work element. The implement carrier has engagement features and locking features to accept and secure any of several implements to the work element. One characteristic of such an implement carrier is that once an implement is attached to it, it is fixed to the implement (i.e., not movable with respect to the implement) and when the implement carrier is moved with respect to the work element, the implement moves with the implement carrier. The term implement carrier is not merely a pivotal connection point, but rather a dedicated device specifically intended to accept and be secured to various different implements. The implement carrier itself is mountable to a work element 130 such as a lift arm structure or the frame 110. Implement interface 170 can also include one or more power sources for providing power to one or more work elements on an implement. Some power machines can have a plurality of work element with implement interfaces, each of which may, but need not, have an implement carrier for receiving implements. Some other power machines can have a work element with a plurality of implement interfaces so that a single work element can accept a plurality of implements simultaneously. Each of these implement interfaces can, but need not, have an implement carrier.

[0024] Frame 110 includes a physical structure that can support various other components that are attached thereto or positioned thereon. The frame 110 can include any number of individual components. Some power machines have frames that are rigid. That is, no part of the frame is movable with respect to another part of the frame. Other power machines have at least one portion that can move with respect to another portion of the frame. For example, excavators can have an upper frame portion that rotates about a swivel with respect to a lower frame portion. Other work vehicles have articulated frames such that one portion of the frame pivots with respect to another portion for accomplishing steering functions. In exemplary embodiments, at least a portion of the power source is located in the upper frame or machine portion that rotates relative to the lower frame portion or undercarriage. The power source provides power to components of the undercarriage portion through the swivel.

[0025] Frame 110 supports the power source 120, which can provide power to one or more work elements 130 including the one or more tractive elements 140, as well as, in some instances, providing power for use by an attached implement via implement interface 170. Power from the power source 120 can be provided directly to any of the work elements 130, tractive elements 140, and implement interfaces 170. Alternatively, power from the power source 120 can be provided to a control system 160, which in turn selectively provides power to the elements that are capable of using it to perform a work function. Power sources for power machines typically include an engine such as an internal combustion engine and a power conversion system such as a mechanical transmission or a hydraulic system that can convert the output from an engine into a form of power that is usable by a work element. Other types of power sources can be incorporated into power machines, including electrical sources or a combination of power sources, known generally as hybrid power sources.

[0026] FIG. 1 shows a single work element designated as work element 130, but various power machines can have any number of work elements. Work elements are typically attached to the frame of the power machine and movable with respect to the frame when performing a work task. In addition, tractive elements 140 are a special case of work element in that their work function is generally to move the power machine 100 over a support surface. Tractive elements 140 are shown separate from the work element 130 because many power machines have additional work elements besides tractive elements, although that is not always the case. Power machines can have any number of tractive elements, some or all of which can receive power from the power source 120 to propel the power machine 100. Tractive elements can be, for example, wheels attached to an axle, track assemblies, and the like. Tractive elements can be rigidly mounted to the frame such that movement of the tractive element is limited to rotation about an axle or steerably mounted to the frame to accomplish steering by pivoting the tractive element with respect to the frame.

[0027] Power machine 100 includes an operator station 150, which provides a position from which an operator can control operation of the power machine. In some power machines, the operator station 150 is defined by an enclosed or partially enclosed cab. Some power machines on which the disclosed embodiments may be practiced may not have a cab or an operator compartment of the type described above. For example, a walk behind loader may not have a cabor an operator compartment, but rather an operating position that serves as an operator station from which the power machine is properly operated. More broadly, power machines other than work vehicles may have operator stations that are not necessarily similar to the operating positions and operator compartments referenced above. Further, some power machines such as power machine 100 and others, whether they have operator compartments or operator positions, may be capable of being operated remotely (i.e., from a remotely located operator station) instead of or in addition to an operator station adjacent or on the power machine. This can include applications where at least some of the operator-controlled functions of the power machine can be operated from an operating position associated with an implement that is coupled to the power machine. Alternatively, with some power machines, a remote-control device can be provided (i.e., remote from both of the power machine and any implement to which is it coupled) that can control at least some of the operator-controlled functions on the power machine.

[0028] FIGS. 2-5 illustrate an excavator 200, which is one particular example of a power machine of the type illustrated in FIG. 1, on which the disclosed embodiments can be employed. Unless specifically noted otherwise, embodiments disclosed below can be practiced on a variety of power machines, with the excavator 200 being only one of those power machines.

[0029] Excavator 200 is described below for illustrative purposes. Not every excavator or power machine on which the illustrative embodiments can be practiced need have all the features or be limited to the features that excavator 200 has. Excavator 200 has a frame 210 that supports and encloses a power system 220 (represented in FIG. 3 as a block, as the actual power system is enclosed within the frame 210). In some embodiments the power system 220 includes an engine that provides a power output to a hydraulic system. The hydraulic system acts as a power conversion system that includes one or more hydraulic pumps for selectively providing pressurized hydraulic fluid to actuators that are operably coupled to work elements in response to signals provided by operator input devices. The hydraulic system also includes a control valve system that selectively provides pressurized hydraulic fluid to actuators in response to signals provided by operator input devices. In other embodiments, the power system includes an electrical power source. In such other embodiments, a hydraulic system may not be needed and actuators on the power machine can be electric actuators instead of hydraulic actuators. The excavator 200 includes a plurality of work elements in the form of a first lift arm structure 230and a second lift arm structure 330 (not all excavators have a second lift arm structure). In addition, excavator 200, being a work vehicle, includes a pair of tractive elements in the form of left and right track assemblies 240A and 240B, which are disposed on opposing sides of the frame 210.

[0030] An operator compartment 250 is defined in part by a cab 252, which is mounted on the frame 210. The cab 252 shown on excavator 200 is an enclosed structure, but other operator compartments need not be enclosed. For example, some excavators have a canopy that provides a roof but is not enclosed A control system, shown as block 260, is provided for controlling the various work elements. Control system 260 includes operator input devices, which interact with the power system 220 to selectively provide power signals to actuators to control work functions on the excavator 200. In some embodiments, the operator input devices include at least two two- axis operator input devices to which operator functions can be mapped.

[0031] Frame 210 includes an upper frame portion or house 211 that is pivotally mounted on a lower frame portion or undercarriage 212 via a swivel joint. The swivel joint includes a bearing, a ring gear, and a slew motor with a pinion gear (not pictured) that engages the ring gear to swivel the machine. The slew motor receives a power signal from the control system 260 to rotate the house 211 with respect to the undercarriage 212. House 211 is capable of unlimited rotation about a swivel axis 214 under power with respect to the undercarriage 212 in response to manipulation of an input device by an operator. Hydraulic or electrical conduits are fed through the swivel joint to provide either pressurized hydraulic fluid or electric power to the tractive elements and one or more work elements such as lift arm structure 330 that are operably coupled to the undercarriage 212.

[0032] The first lift arm structure 230 is mounted to the house 211 via a swing mount 215. (Some excavators do not have a swing mount of the type described here.) The first lift arm structure 230 is a boom-arm lift arm of the type that is generally employed on excavators although certain features of this lift arm structure may be unique to the lift arm illustrated in FIGs. 2-3. The swing mount 215 includes a frame portion 215A and a lift arm portion 215B that is rotationally mounted to the frame portion 215A at a mounting frame pivot 231 A. A swing actuator 233A is coupled to the house 211 and the lift arm portion 215B of the mount. Actuationof the swing actuator 233A causes the lift arm structure 230 to pivot or swing about an axis that extends longitudinally through the mounting frame pivot 231 A.

[0033] The first lift arm structure 230 includes a first portion 232, known generally as a boom, and a second portion 234, known as an arm or a dipper. The boom 232 is pivotally attached on a first end 232A to mount 215 at boom pivot mount 231B. A boom actuator 233B is attached to the mount 215 and the boom 232. Actuation of the boom actuator 233B causes the boom 232 to pivot about the boom pivot mount 23 IB, which effectively causes a second end 232B of the boom to be raised and lowered with respect to the house 211. A first end 234A of the arm 234 is pivotally attached to the second end 232B of the boom 232 at an arm mount pivot 231C. An arm actuator 233C is attached to the boom 232 and the arm 234. Actuation of the arm actuator 233C causes the arm to pivot about the arm mount pivot 231C. Each of the swing actuator 233A, the boom actuator 233B, and the arm actuator 233C can be independently controlled in response to control signals from operator input devices.

[0034] An exemplary implement interface 270 is provided at a second end 234B of the arm 234. The implement interface 270 includes an implement carrier 272 that can accept and securing a variety of different implements to the lift arm structure 230. Such implements have a machine interface that is configured to be engaged with the implement carrier 272. The implement carrier 272 is pivotally mounted to the second end 234B of the arm 234. An implement carrier actuator 233D is operably coupled to the arm 234 and a linkage assembly 276. The linkage assembly includes a first link 276A and a second link 276B. The first link 276A is pivotally mounted to the arm 234 and the implement carrier actuator 233D. The second link 276B is pivotally mounted to the implement carrier 272 and the first link 276A. The linkage assembly 276 is provided to allow the implement carrier 272 to pivot about the arm 234 when the implement carrier actuator 233D is actuated.

[0035] The implement interface 270 also includes an implement power source (not shown) available for connection to an implement on the lift arm structure 230. In some embodiments, the implement power source includes pressurized hydraulic fluid port to which an implement can be coupled. The pressurized hydraulic fluid port selectively provides pressurized hydraulic fluid for powering one or more functions or actuators on an implement. In addition, or in the alternative, the implement power source can include an electrical power source for powering electricalactuators and / or an electronic controller on an implement. The electrical power source can also include electrical conduits that are in communication with a data bus on the excavator 200 to allow communication between a controller on an implement and electronic devices on the excavator 200.

[0036] The lower frame 212 supports and has attached to it a pair of tractive elements, identified in FIG. 2-3 as left track drive assembly 240 A and right track drive assembly 240B. Each of the tractive elements 240A, 240B has a track frame 242 that is coupled to the lower frame 212. The track frame 242 supports and is surrounded by an endless track 244, which rotates under power to propel the excavator 200 over a support surface. Various elements are coupled to or otherwise supported by the track frame 242 for engaging and supporting the track 244 and cause it to rotate about the track frame. For example, a sprocket 246 is supported by the track frame 242 and engages the endless track 244 to cause the endless track to rotate about the track frame. An idler 245 is held against the track 244 by a tensioner (not shown) to maintain proper tension on the track. The track frame 242 also supports a plurality of rollers 248, which engage the track and, through the track, the support surface to support and distribute the weight of the excavator 200. An upper track guide 249 provides tension on track 244 and prevents the track from rubbing on track frame 242.

[0037] A second, or lower, lift arm structure 330 is pivotally attached to the lower frame 212. A lower lift arm actuator 332 is pivotally coupled to the lower frame 212 at a first end 332A and to the lower lift arm structure 330 at a second end 332B. The lower lift arm structure 330 is configured to carry a lower implement 334, which in one embodiment is a blade as is shown in FIGS. 2-3. The lower implement 334 can be rigidly fixed to the lower lift arm structure 330 such that it is integral to the lift arm structure. Alternatively, the lower implement can be pivotally attached to the lower lift arm structure via an implement interface, which in some embodiments can include an implement carrier of the type described above. Lower lift arms with implement interfaces can accept and secure various different types of implements thereto. Actuation of the lower lift arm actuator 332, in response to operator input, causes the lower lift arm structure 330 to pivot with respect to the undercarriage or lower frame 212, thereby raising and lowering the lower implement 334.

[0038] Upper frame portion or house 211 supports cab 252, which defines, at least in part, operator compartment or station 250. A seat 254 is provided within cab 252 in which an operator can be seated while operating the excavator. While sitting in the seat 254, an operator will have access to a plurality of operator input devices 256 that the operator can manipulate to control various work functions, such as manipulating the lift arm structure 230, the lower lift arm structure 330, the traction system 240A, 240B, pivoting the house 211 and so forth.

[0039] Excavator 200 provides a variety of different operator input devices 256 to control various functions. In one embodiment, joysticks (such as hydraulic or electric joysticks) can be provided to control the lift arm structure 230 and swiveling of the house 211 of the excavator. Foot pedals with attached levers are provided for controlling travel and lift arm swing. Electrical switches are located on the joysticks for controlling the providing of power to an implement attached to the implement carrier 272. Other types of operator inputs that can be used in excavator 200 and other excavators and power machines include, but are not limited to, switches, buttons, knobs, levers, variable sliders, roller-ball inputs and the like. The specific control examples provided above are exemplary in nature and not intended to describe the input devices for all excavators and what they control.

[0040] Display devices are provided in the cab to give indications of information relatable to the operation of the power machines in a form that can be sensed by an operator, such as, for example audible and / or visual indications. Audible indications can be made in the form of buzzers, bells, and the like or via verbal communication. Visual indications can be made in the form of graphs, lights, icons, gauges, alphanumeric characters, and the like. Displays can provide dedicated indications, such as warning lights or gauges, or dynamic to provide programmable information, including programmable display devices such as monitors of various sizes and capabilities. Display devices can provide diagnostic information, troubleshooting information, instructional information, and various other types of information that assists an operator with operation of the power machine or an implement coupled to the power machine. Other information that may be useful for an operator can also be provided.

[0041] The description of power machine 100 and excavator 200 above is provided for illustrative purposes, to provide illustrative environments on which the embodiments discussed below can be practiced. While the embodiments discussed can be practiced on a power machinesuch as is generally described by the power machine 100 shown in the block diagram of FIG. 1 and more particularly on an excavator such as excavator 200, unless otherwise noted, the concepts discussed below are not intended to be limited in their application to the environments specifically described above.

[0042] FIG. 4 is a side elevation view of an exemplary excavator 200 in a first mode configuration, wherein the implement 180, configured as a bucket as illustrated, generally faces inward toward the operator compartment 250. The implement 180 configured as a bucket generally has an open side 278 (or working side with an implement having another configuration). When the implement 180 is relatively aligned with a downwardly extending arm 234 (there is little pivot at linkage 276), the implement 180 is considered to be inward facing when its open side 278 faces the operator compartment 250 of the excavator 200. When the bucket 180 is attached to the first lift arm structure 230 with an inwardly facing open side 278, it is configured primarily for use as a traditional excavator, designed to move the implement 180 in a substantially radial orientation as illustrated. Moreover, much of the operation of the bucket or implement 180 is at or below grade or ground level 280.

[0043] FIG. 5 is a side elevation view of an exemplary excavator 200 in a second mode configuration, wherein the implement 180, configured as a bucket as illustrated, generally faces outward, away from the operator compartment 250. The implement 180 configured as a bucket generally has an open side 278. When the implement 180 is relatively aligned with a downwardly extending arm 234 (there is little pivot at linkage 276), the implement 180 is considered to be outward facing when its open side 278 faces away the operator compartment 250 of the excavator 200. When the bucket 180 is attached to the first lift arm structure 230 with an outwardly facing open side 278, it is configured primarily for use as a loader, designed to move the implement 180 in a substantially vertical, self-leveling motion as illustrated. Moreover, much of the operation of the bucket or implement 180 is at or above grade or ground level 280.

[0044] Many work sites use both an excavator and a loader. With the described concepts, a single power machine 100, 200 can serve both purposes. In a first mode, as illustrated in FIGS. 4 and 7A, the excavator 200 provides traditional excavator functions such as digging, trenching, and dumping, for example. In a second mode, as illustrated in FIGS. 5 and 7B, the excavator 200 provides traditional loader functions such as scooping, lifting, moving, and unloading, forexample. While the same implement is shown in both FIGS. 4 and 5, in some cases, the second mode can utilize a more standard loader implement such as a loader style bucket or a pallet fork, for example. By changing modes (and optionally implements), a single power machine 100, 200 can perform the functions more typically performed by plural power machines. This greatly increases the versatility of the power machine and enhances it flexibility in use.

[0045] FIG. 6 is a simplified block diagram that illustrates some functions of a control system 460 for use in a power machine 400, which can be similar to the excavator 200 discussed above. It should be appreciated that a control system for a power machine such as excavator 200 or any other power machine can be more complex than the control system 460 as shown in FIG. 6 and that the simplification of the control system 460 is provided to focus on key features of the control system.

[0046] Control system 460 includes a controller 462, which can be any suitable electronic controller capable of receiving a plurality of input signals from various input devices and providing output signals for controlling actuation devices. The control system 460 also includes a mode input 464, which is manipulable by an operator to select a mode of operation for controlling functions on the machine via actuation devices. In one embodiment, the control system 460 is configured to operate in a first mode and in a second mode. FIGS. 7A and 7B illustrate examples of first and second modes, with a first mode shown in FIG. 7A being identified as an “excavator mode” and the second mode shown in FIG. 7B being identified as a “loader mode.” Control system 460 also includes operator inputs that are manipulable by an operator for providing electrical control signals to the controller 462 indicative of an operator’s intention to control a machine function. As illustrated in FIG. 6, the operator inputs include a pair of joysticks: first two-axis joystick 466 and second two-axis joystick 468. The first and second joysticks in various embodiments can be different types of joysticks that can provide voltage or current signals to the controller 460 or serial communication streams, either via a wired or wireless connection.

[0047] Controller 462 is also operably coupled to a plurality of actuators that are configured to control machine functions on the power machine 400. These actuators illustratively include one or more drive actuators 470 for controlling the tractive effort of the power machine. These drive actuators can be, for example, one or more drive pumps in a hydrostatic drive system, aplurality of valves in a hydraulic drive system, or one or more electric motors in an electric drive system. One or more house slew actuators 472 are coupled to the controller. The house slew actuators 472 can rotate a house with respect to an undercarriage. Lift arm and bucket actuators 474 control the positioning of the lift arm structure and implement. Blade control actuator 476 control the position of a lower implement on a house such as blade 334 shown in FIGS. 2-3.

[0048] FIGS. 7A and 7B illustrate a pair of two-axis joysticks 466 and 468 as they operate in first and second modes according to one illustrative embodiment. As shown in FIG. 7A, in a first mode, the “excavator” mode, the first and second joysticks are designated as 466A and 468A, respectively. As shown in FIG. 7B, in a second mode, the “loader” mode, the first and second joysticks are designated as 466B and 468B, respectively.

[0049] As shown in FIG. 7A, in the “excavator” mode, an operator is typically operating the lift arm structure to dig and remove soil, as shown in FIG. 4, for example. During a work cycle, the operator is most often manipulating the lift arm structure and rotation of the house. In this mode, the first joystick 466A is configured to provide two inputs: one axis of movement signals an intent to rotate the house and a second axis of movement signals an intent to move an arm portion of the lift arm structure in and out. The arm portion 234 of the lift arm structure 230, for reference, is the distal portion of a lift arm structure 230 (such as illustrated in FIGS. 2-3). The second joystick 468A controls movement of the boom portion of a lift arm structure (i.e., boom portion 232) and the implement (“bucket dump” and “bucket curl”). “Bucket dump” pivots the implement outward at linkage assembly 276, and “bucket curl” pivots the implement inward at linkage assembly 276. In this “excavator” mode, the first and second joysticks are optimized to dig and dump material such as might be done when digging a trench.

[0050] Referring to FIGS. 5 and 7B, in the “loader” mode, the implement is attached to the excavator 200 in an outward facing manner, which is the opposite of its orientation in the “excavator” mode of FIG. 4. An operator is primarily concerned with controlling travel of the machine and motions that lift, lower, and pivot the implement. In the “loader” mode, the first joystick (designed as 466B to signify second mode operation) controls the direction and speed of travel. In a first axis, the first joystick 466B controls speed and direction (i.e., “forward” and “back”). In a second axis, the first joystick 466B controls turning direction and amount (i.e., “left” and “right”). It should be said that in all these instances, most two-axis joysticks allowsimultaneous input from both joysticks. In the “loader” mode, the second joystick 468B controls the lift arm structure to control the vertical position of the implement in one axis (“lower workgroup” and “lift workgroup”) and pivoting of the implement in the other axis (“implement roll-in” and “implement roll-out”). Controlling the vertical position of the implement can include controlling a combination of the boom actuator 233B and the arm actuator 233 C based upon movement of the second joystick 468B.

[0051] FIG. 8 illustrates a method 500 of selecting a mode of operation for user input devices on a power machine according to one illustrative embodiment. The method 500 is described with reference to the control system 460 of FIG. 6 to provide an exemplary reference for understanding the method. The method begins at block 502 when mode input 464 provides an indication that it has been actuated to controller 462. When this indication is provided, the controller 462 analyzes and determines at block 504 whether it is indicating mode 1 (or alternatively which mode is selected). It should be appreciated that the embodiment here illustrates two modes of operation, but in other embodiments, more than two modes of operation can be employed. If it is determined at block 504 that mode 1 is selected, the method moves to block 506 and the controller 462 is configured to analyze the inputs from the first and second joysticks 466 and 468 according to a first mode (such as the “excavator” mode illustrated in FIG. 7A). If, however, it is determined at block 506 that the mode 1 is not selected (or that mode 2 is selected), the method moves to block 508 and the controller 462 is configured to analyze the inputs from the first and second joysticks 466 and 468 according to a second mode (such as the “loader” mode illustrated in FIG. 7B).

[0052] Although not shown in the above, in some embodiments, either of the first and second modes may be a default mode such that at startup, determined by the orientation of the implement as being inward-facing as shown in FIG. 4 or outward-facing as shown in FIG. 5. If the implement is inward-facing as shown in FIG. 4, the default mode is the “excavator” mode, with joystick controls as shown in FIG. 7A. If the implement is outward-facing as shown in FIG. 5, the default mode is the “loader” mode, with joystick controls as shown in FIG. 7B. The control system 460 defaults to that mode in the absence of any signal from the mode input 464. In other embodiments, the control system 460 may require an input from a mode input 464 before operating in any mode.

[0053] Exemplary, non-limiting embodiments of an apparatus and method are described. While these descriptions relate to the illustrative embodiments for ease of understanding, it is to be understood that the subject matter is not limited to these examples. In an exemplary embodiment, an excavator 200 comprises a frame 510 and a first lift arm structure 230. A controller 462 is communicatively coupled to a first operator input device 466, a second operator input device 468 and a mode selection input 464, wherein the controller 462 is configured to determine a selected mode of operation (FIG. 7A or FIG. 7B) based upon an indication provided by the mode selection input 502, and to analyze inputs from the first operator input device 466 and the second operator input device 468 based upon the determined selected mode of operation to control machine functions, responsive to the operator's manipulation of the first operator input device 466 and the second operator input device 468. When the selected mode of operation is a first mode of operation (FIG. 7A), a first set of machine functions is controlled by the operator's manipulation of the first operator input device 466A and the second operator input device 468A. When the selected mode of operation is a second mode of operation (FIG. 7B), a second set of machine functions is controlled by the operator's manipulation of the first operator input device 466B and the second operator input device 468B. The first set (FIG. 7A) includes at least one machine function that is not a part of the machine functions in the second set (FIG. 7B). A first machine function (for example bucket dump / bucket curl and implement roll-in / implement rollout) is included in each of the first set of machine functions (FIG. 7A) and the second set of machine functions (FIG. 7B). In an exemplary embodiment, bucket dump / bucket curl and implement roll-in / implement roll-out are considered to be the same machine function in both the first and second modes; they are given different terminology because in the second mode shown in FIG. 7B, the implement may be a more conventional loader implement rather than a bucket. In an exemplary embodiment, the first machine function is controlled using the second operator input device (468) in both the first mode of operation (FIG. 7A) and in the second mode of operation (FIG. 7B). In an exemplary embodiment, bucket dump of FIG. 7A and implement roll-in of FIG. 7B are different terms for the same machine function, using the same actuator(s) to affect the same movement of an implement 180 about linkage 276 (although the implement may be oriented differently relative to arm 234 in the first mode of FIG. 7A versus the second mode of FIG. 7B). In an exemplary embodiment, bucket curl of FIG. 7A and implement roll-outof FIG. 7B are different terms for the same machine function, using the same actuator(s) to affect the same movement of an implement 180 about linkage 276 (although the implement may be oriented differently relative to arm 234 in the first mode of FIG. 7A versus the second mode of FIG. 7B).

[0054] An exemplary method of selecting a mode of operation for first and second user input devices 466, 468 on an excavator 200 and controlling the excavator 200 is described. In an exemplary embodiment, the excavator comprises a frame 210 comprising an upper structure 211 and a lower structure 212, a lift arm structure 230 comprising a boom 232 and an arm 234, and a plurality of actuators 233A, 233B, 233C, 233D, 470, 472, 474. In an exemplary embodiment, a first end of the boom 232 is pivotally coupled to the frame 210, and a first end of the arm 234 is pivotally coupled to a second end of the boom 232. In an exemplary embodiment, the lift arm structure 230 is configured to have an implement 180 coupled to a second end of the arm 234. An exemplary method comprises receiving a mode selection input 502 from a mode selection input device 464 and determining a selected mode of operation, from at least two modes of operation, based upon the mode selection input. An exemplary method comprises configuring a controller 462 to analyze inputs from the first and second user input devices 466, 468 based upon the determined selected mode of operation and controlling machine functions, responsive to an operator's manipulation of the first and second user input devices 466, 468, using the configured controller 462. An exemplary method comprises controlling the plurality of actuators using the first and second user inputs in a first mode of operation (FIG. 7A) and a second mode of operation (FIG. 7B). In the first mode of operation, a first subset of the plurality of actuators is controlled to provide: a first function relating to a rotational position of the upper structure relative to the lower structure, a second function relating to movement of the boom relative to the upper structure, a third function relating to movement of the arm relative to the boom, and a fourth function relating to movement of the implement relative to the arm (such as bucket dump and bucket curl). In the second mode of operation, a second subset of the plurality of actuators is controlled to provide the fourth function relating to movement of the implement relative to the arm (such as implement roll-in and implement roll-out), a fifth function relating to travel of the excavator, and a sixth function relating to vertical motion of the lift arm structure.

[0055] In an exemplary embodiment, a power machine 100, 200 comprises a frame 110, 210; an operator compartment 150, 250 supported by the frame 110, 210; a lift arm structure 130, 230 coupled to the frame 110, 210; an implement 180 configured for attachment to the lift arm structure 130, 230; a plurality of actuators 233 A, 233B, 233C, 233D, 470, 472, 474; a first operator input device 466, 468; and a controller 160, 260, 462. The implement 180 is configured for attachment to the lift arm structure 130, 230 in a first orientation that faces toward the operator compartment as shown in FIG. 4, corresponding with a first (excavator) mode of machine operation. Alternatively, the implement 180 is configured for attachment to the lift arm structure 130, 230 in a second orientation that faces away from the operator compartment as shown in FIG. 5, corresponding with a second (loader) mode of machine operation.

[0056] The first operator input device 466, 468 is positioned in the operator compartment 150, 250 and is configured to be manipulated by an operator. In the first (excavator) mode shown in FIG. 7A, a first motion of either input device 466, 468 responsively provides a first control signal. Alternatively, in the second (loader) mode shown in FIG. 7B, the same first motion of the same input device 466, 468 responsively provides a second control signal. The controller 160, 260, 462 is coupled to the input device 466, 468 and is configured: to activate, in the first mode, at least one of the plurality of actuators responsive to the first control signal to perform a first machine function; or to activate, in the second mode, at least one of the plurality of actuators responsive to the second control signal to perform a second machine function that is different from the first machine function. For example, in the case in which we are considering the first mode (excavator mode) of FIG. 7A, with the right joystick 468A as the first input device, and the first motion being an upward push on the joystick, the first machine function would be to move the “boom down.” In a corresponding second mode (loader mode) of FIG. 7B, with the right joystick 468B as the first input device, and the same first motion being an upward push on the joystick, the second machine function would be “lower workgroup.”

[0057] In an exemplary embodiment, a second operator input device (the other joystick, for example) is positioned in the operator compartment and is configured to be manipulated by the operator: in the first mode, with a second motion, to responsively provide a third control signal; or in the second mode, with the second motion, to responsively provide a fourth control signal. In an exemplary embodiment, the controller is coupled to the second operator input device andconfigured: to activate, in the first mode, at least one of the plurality of actuators responsive to the third control signal to perform a third machine function; or to activate, in the second mode, at least one of the plurality of actuators responsive to the fourth control signal to perform a fourth machine function that is different from the third machine function. For example, in the case in which we are considering the first mode (excavator mode) of FIG. 7A, with the left joystick 466A as the second input device, and the second motion being an upward push on the left joystick, the third machine function would be to move the “arm out.” In a corresponding second mode (loader mode) of FIG. 7B, with the left joystick 466B as the second input device, and the second motion being an upward push on the left joystick, the fourth machine function would be to move the machine “forward.”

[0058] In an exemplary embodiment, at least one of the first operator input device 466, 468 and the second operator input device 466, 468 is a two-axis joystick. In an exemplary embodiment, a mode selection input 502 is configured to be manipulated by the operator, and to responsively provide an indication to the controller 160, 260, 462 of a selection of either the first (excavator) mode or the second (loader) mode. In an exemplary embodiment, a plurality of tractive elements 140, 240A, 240B are coupled to the frame 110, 210. In an exemplary embodiment, the lift arm structure comprises a boom portion 232 and an arm portion 234. In an exemplary embodiment, the implement 180 is attached to the arm portion 234.

[0059] In an exemplary embodiment, the plurality of actuators comprises a drive actuator 470 configured to control at least one of the plurality of tractive elements 140, 240A, 240B; a boom actuator 233B, 474 configured to control a position of the boom portion 232 relative to the frame 110, 210; an arm actuator 233C, 474 configured to control a position of the arm portion 234 relative to the boom portion 232; and an implement actuator 233D, 474 configured to control a position of the implement 180 relative to the arm portion 234. In an exemplary embodiment, the frame 110, 210 comprises a house 211 rotationally coupled to an undercarriage 212. In an exemplary embodiment, the plurality of actuators comprises a slew actuator 472 configured to control rotation of the house 211 relative to the undercarriage 212.

[0060] An exemplary method of controlling a power machine 100, 200 comprises determining a selected mode of operation from at least a first mode (such as an excavator mode, for example) and a second mode (such as a loader mode, for example) and using a controller todirect the performance of different machine functions based upon the selected mode, even when the input motion into an operator input device 466, 468 is the same.

[0061] The embodiments discussed above provide important advantages. The joystick input devices are easily manipulable and are well suited to control various machine functions. By selecting between different control modes, the joysticks can be configured so that an operator can perform specific tasks more easily. For example, by having a mode for controlling drive and level lifting / lowering of implement, the excavator can be operated in a mode that is more closely associated with a loader. The same machine can be, in a separate mode, operated more like a traditional excavator.

[0062] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the scope of the discussion.

Claims

WHAT IS CLAIMED IS:I . An excavator comprising: a frame; a first lift arm structure configured to be moved relative to the frame, the first lift arm structure comprising a boom portion and an arm portion, the arm portion configured to have a first implement mounted thereto by an implement interface; a controller communicatively coupled to a first operator input device, a second operator input device and a mode selection input, wherein the controller is configured to determine a selected mode of operation, from at least two modes of operation, based upon an indication provided by the mode selection input, and to analyze inputs from the first operator input device and the second operator input device based upon the determined selected mode of operation to control machine functions, responsive to the operator's manipulation of the first operator input device and the second operator input device such that: when the selected mode of operation is a first mode of operation, a first set of machine functions is controlled by the operator's manipulation of the first operator input device and the second operator input device; when the selected mode of operation is a second mode of operation, a second set of machine functions is controlled by the operator's manipulation of the first operator input device and the second operator input device; wherein the first set includes at least one machine function that is not a part of the machine functions in the second set; and wherein a first machine function is included in each of the first set of machine functions and the second set of machine functions, and wherein the first machine function is controlled using the second operator input device in both the first mode of operation and in the second mode of operation.

2. The excavator of claim 1 wherein the frame comprises: an undercarriage; anda house configured to rotate with respect to the undercarriage.

3. The excavator of claim 2 comprising a second lift arm structure configured to be moved relative to the undercarriage, the second lift arm structure having a second implement secured thereto.

4. The excavator of claim 2, wherein the house comprises an operator compartment.

5. The excavator of claim 2, comprising: a drive actuator configured to control at least one tractive element; a boom actuator configured to control a position of the boom portion relative to the house; an arm actuator configured to control a position of the arm portion relative to the boom portion; and an implement actuator configured to control a position of the first implement relative to the arm portion.

6. The excavator of claim 2, comprising a slew actuator configured to control rotation of the house relative to the undercarriage.

7. The excavator of claim 1, wherein the first machine function comprises pivoting the first implement relative to the arm portion.

8. The excavator of claim 1, wherein: in the first mode of operation, the first implement faces toward the frame; and in the second mode of operation, the first implement faces away from the frame.

9. The excavator of claim 1, wherein at least one of the first operator input device or the second operator input device is a multi-axis joystick.

10. A method of selecting a mode of operation for first and second user input devices on an excavator and controlling the excavator, the excavator comprising: a frame comprising an upper structure and a lower structure; a lift arm structure comprising a boom and an arm, wherein a first end of the boom is pivotally coupled to the frame, and wherein a first end of the arm is pivotally coupled to a second end of the boom, and wherein an implement is configured to be coupled to a second end of the arm; and a plurality of actuators; the method comprising: receiving a mode selection input from a mode selection input device; determining a selected mode of operation, from at least two modes of operation, based upon the mode selection input; configuring a controller to analyze inputs from the first and second user input devices based upon the determined selected mode of operation and controlling machine functions, responsive to an operator's manipulation of the first and second user input devices, using the configured controller; and controlling the plurality of actuators using the first and second user inputs in a first mode of operation and a second mode of operation, wherein: in the first mode of operation, a first subset of the plurality of actuators is controlled to provide: a first function relating to a rotational position of the upper structure relative to the lower structure; and responsive to the second user input device, a second function relating to movement of the implement relative to the arm; and in the second mode of operation, a second subset of the plurality of actuators is controlled to provide: responsive to the second user input device, the second function relating to movement of the implement relative to the arm; and a third function relating to travel of the excavator.

11. The method of claim 10, wherein receiving the mode selection input from the mode selection input device comprises determining an absence of a signal from the mode selection input device, and wherein determining the selected mode of operation comprises selecting a default mode of operation from the at least two modes of operation.

12. The method of claim 10, wherein determining the selected mode of operation further comprises determining whether the first mode of operation is selected, and if it is determined that the first mode of operation is selected then configuring the controller comprises configuring the controller to analyze inputs based upon the first mode of operation.

13. The method of claim 12, wherein if it is determined that the first mode of operation is not selected, then determining that the second mode of operation is selected and then configuring the controller comprises configuring the controller to analyze inputs based upon the second mode of operation.

14. The method of claim 10, wherein the at least two modes of operation include an excavator mode of operation and a loader mode of operation.

15. The method of claim 10, wherein in the first mode of operation, the first subset of the plurality of actuators is controlled to provide a fourth function relating to movement of the boom relative to the upper structure.

16. The method of claim 15, wherein in the first mode of operation, the first subset of the plurality of actuators is controlled to provide a fifth function relating to movement of the arm relative to the boom.

17. The method of claim 16, wherein in the first mode of operation, the first subset of the plurality of actuators is controlled to provide the first function responsive to the first user input device, the fourth function responsive to the second user input device, and the fifth function responsive to the first user input device.

18. The method of claim 17, wherein in the second mode of operation, the second subset of the plurality of actuators is controlled to provide a sixth function, responsive to the second user input device, relating to vertical motion of the implement.

19. The method of claim 18, wherein the plurality of actuators includes a boom actuator configured to control a position of the boom relative to the upper structure and an arm actuator configured to control a position of the arm relative to the boom, and wherein in the second mode of operation, the sixth function is provided by controlling both of the boom actuator and the arm actuator responsive to the second user input device.

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