WORK VEHICLE MAGNETORHEOLOGICAL FLUID JOYSTICK SYSTEMS PROVIDING MACHINE STATE FEEDBACK
Embodiments of a work vehicle magnetorheological fluid (MRF) joystick system include a joystick device, an MRF joystick resistance mechanism, a controller architecture, and a work vehicle sensor configured to provide sensor data indicative of an operational parameter pertaining to work vehicle. The MRF joystick resistance mechanism is controllable to vary an MRF resistance force resisting movement of a joystick included in the joystick device relative to a base housing thereof. The controller architecture is configured to: (i) monitor for variations in the operational parameter utilizing the sensor data; and (ii) provide tactile feedback through the joystick device indicative of the operational parameter by selectively commanding the MRF joystick resistance mechanism to adjust the MRF resistance force impeding joystick movement based, at least in part, on variations in the operational parameter.
This application claims priority to U.S. provisional application Ser. No. 63/019,083, filed with the United Stated Patent and Trademark Office on May 1, 2020.
STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENTNot applicable.
FIELD OF THE DISCLOSUREThis disclosure relates to magnetorheological fluid (MRF) joystick systems, which selectively vary joystick resistances to provide feedback indicative of monitored operational parameters or machine states of work vehicles.
BACKGROUND OF THE DISCLOSUREJoystick devices are commonly utilized to control various operational aspects of work vehicles employed within the construction, agriculture, forestry, and mining industries. For example, in the case of a work vehicle equipped with a boom assembly, an operator may utilize one or more joystick devices to control boom assembly movement and, therefore, movement of a tool or implement mounted to an outer terminal end of the boom assembly. Common examples of work vehicles having such joystick-controlled boom assemblies include excavators, feller bunchers, skidders, tractors (on which modular front end loader and backhoe attachments may be installed), tractor loaders, wheel loaders, and various compact loaders. Similarly, in the case of dozers, motor graders, and other work vehicles equipped with earth-moving blades, an operator may utilize with one or more joysticks to control blade movement and positioning. Joystick devices are also commonly utilized to steer or otherwise control the directional movement of the work vehicle chassis in the case of motor graders, dozers, and certain loaders, such as skid steer loaders. Given the prevalence of joystick devices within work vehicles, taken in combination with the relatively challenging, dynamic environments in which work vehicles often operate, a continued demand exists for advancements in the design and function of work vehicle joystick systems, particularly to the extent that such advancements can improve the safety and efficiency of work vehicle operation.
SUMMARY OF THE DISCLOSUREA work vehicle magnetorheological fluid (MRF) joystick system is disclosed for usage onboard a work vehicle. In embodiments, the work vehicle MRF joystick system includes a joystick device, an MRF joystick resistance mechanism, a controller architecture, and a work vehicle sensor configured to provide sensor data indicative of an operational parameter pertaining to the work vehicle. The joystick device includes, in turn, a base housing, a joystick movably mounted to the base housing, and a joystick position sensor configured to monitor movement of the joystick relative to the base housing. The MRF joystick resistance mechanism is controllable to vary an MRF resistance force inhibiting or resisting movement of the joystick relative to the base housing in at least one degree of freedom (DOF). The controller architecture is coupled to the joystick position sensor, to the work vehicle sensor, and to the MRF joystick resistance mechanism. The controller architecture is configured to: (i) monitor for variations in the operational parameter utilizing the sensor data; and (ii) provide tactile feedback through the joystick device indicative of the operational parameter by selectively commanding the MRF joystick resistance mechanism to adjust the MRF resistance force based, at least in part, on variations in the operational parameter.
In further embodiments, the work vehicle MRF joystick system includes a joystick device, an MRF joystick resistance mechanism, and a controller architecture. Once again, the joystick device includes a base housing, a joystick movably mounted to the base housing, and a joystick position sensor configured to monitor movement of the joystick relative to the base housing. The MRF joystick resistance mechanism is controllable to vary an MRF resistance force resisting movement of the joystick relative to the base housing in at least one DOF. The controller architecture, coupled to the joystick position sensor and to the MRF joystick resistance mechanism, is configured to: (i) monitor a current ground speed of the work vehicle; and (ii) selectively command the MRF joystick resistance mechanism to adjust the MRF resistance force based, at least in part, on the current ground speed of the work vehicle.
In still further embodiments, the MRF joystick system is utilized onboard a work vehicle equipped with a boom-mounted implement. The MRF joystick system includes a joystick device, an MRF joystick resistance mechanism, and a controller architecture. The joystick device includes, in turn, a base housing, a joystick movably mounted to the base housing, and a joystick position sensor configured to monitor movement of the joystick relative to the base housing. The MRF joystick resistance mechanism is controllable to vary an MRF resistance force resisting movement of the joystick relative to the base housing in at least one DOF. Coupled to the joystick position sensor and to the MRF joystick resistance mechanism, the controller architecture is configured to: (i) estimate a variable load resisting movement of the boom-mounted implement in at least one direction, and (ii) selectively command the MRF joystick resistance mechanism to increase the MRF resistance force as the variable load increases.
The details of one or more embodiments are set-forth in the accompanying drawings and the description below. Other features and advantages will become apparent from the description, the drawings, and the claims.
At least one example of the present disclosure will hereinafter be described in conjunction with the following figures:
Like reference symbols in the various drawings indicate like elements. For simplicity and clarity of illustration, descriptions and details of well-known features and techniques may be omitted to avoid unnecessarily obscuring the example and non-limiting embodiments of the invention described in the subsequent Detailed Description. It should further be understood that features or elements appearing in the accompanying figures are not necessarily drawn to scale unless otherwise stated.
DETAILED DESCRIPTIONEmbodiments of the present disclosure are shown in the accompanying figures of the drawings described briefly above. Various modifications to the example embodiments may be contemplated by one of skill in the art without departing from the scope of the present invention, as set-forth the appended claims. As appearing herein, the term “work vehicle” includes all parts of a work vehicle or work machine. Thus, in implementations in which a boom assembly terminating in an implement is attached to the chassis of a work vehicle, the term “work vehicle” encompasses both the chassis and the boom assembly, as well as the implement or tool mounted to the terminal end of the boom assembly.
OverviewThe following describes work vehicle joystick systems incorporating magnetorheological fluid (MRF) devices or subsystems, which provide tactile feedback indicative of monitored operational parameters or “machine states” of work vehicles. During work vehicle operation, the below-described work vehicle MRF joystick system receives sensor data indicative of at least one monitored parameter of a given work vehicle; and selectively vary an MRF resistance force impeding joystick movement in at least one degree of freedom (DOF) based, at least in part, on joystick position and variations in the monitored parameter. In so doing, the work vehicle MRF joystick system provides work vehicle operators with tactile feedback indicative of the current state or magnitude of the monitored operational parameter or machine state. As the tactile feedback is provided through the joystick device itself, this information is conveyed to the operator in a highly intuitive, rapid manner and without requiring the operator to avert visual attention from the work task at hand. Further, in at least some embodiments, the tactile feedback provided through the below-described joystick devices may help guide or influence operator control inputs to promote smooth or non-abrupt work vehicle operation, to increase uniformity between operator expectations and work vehicle performance, and to provide similar benefits. Overall operator satisfaction levels and work vehicle efficiency may be improved as a result.
Embodiments of the work vehicle MRF joystick system include a processing sub-system or “controller architecture,” which is coupled to an MRF damper or an MRF joystick resistance mechanism; that is, a mechanism or device containing a magnetorheological fluid and capable of modifying the rheology (viscosity) of the fluid through variations in the strength of an electromagnetic (EM) field to provide controlled adjustments to the resistive force impeding joystick motion in at least one DOF. This resistive force is referred to below as an “MRF resistance force,” while the degree to which an MRF resistance force impedes joystick motion in a particular direction or combination of directions is referred to as the “joystick stiffness.” The MRF joystick resistance mechanism may be commanded by the controller architecture to apply various different resistive effects selectively impeding joystick rotation or other joystick motion in any given direction, over any given range of travel of the joystick, and through the application of varying magnitudes of resistive force. For example, embodiments of the MRF joystick system may progressively increase joystick stiffness in proportion to changes in certain monitored parameters; e.g., in embodiment, and as discussed in detail below, the controller architecture may command the MRF joystick resistance mechanism to increase the MRF resistance force (and, therefore, joystick stiffness) as a monitored parameter, such as a material load, a hydraulic pressure, or work vehicle ground speed, increases in magnitude. Additionally or alternatively, embodiments of the MRF joystick system may generate other MRF-applied effects, such as detent or pulsating effects, briefly impeding joystick motion as a monitored parameter surpasses predetermined thresholds. Further, embodiments of the MRF joystick control system may be capable of increasing joystick stiffness in a single DOF or, instead, of independently increasing joystick stiffness in multiple DOFs. For example, in implementations which a joystick is rotatable about two perpendicular axes, the MRF joystick resistance mechanism may be capable of independently vary joystick stiffnesses about the two rotational axes of the joystick.
The work vehicle MRF joystick system provides a high level of flexibility, both from design and customization standpoints. Regarding design flexibility, the MRF joystick system can be configured to vary joystick stiffness in response to a wide range of monitored parameters pertaining to work vehicles of varying types employed in construction, agriculture, mining, and forestry industries. A non-exhaustive list of such monitored parameters includes work vehicle ground speed (particularly in the case of joystick-steered work vehicles), the proximity of movable work vehicle components (e.g., boom assembly joints or hydraulic cylinders) to motion stops, and various loads placed on a work vehicle. In the latter regard, embodiments of the MRF joystick system may monitor, and selectively vary the MRF joystick resistance force based upon, material loads carried by the work vehicle, such as the fill load of a bucket attached to a boom assembly. Similarly, in embodiments, the MRF resistance force and joystick stiffness in at least one DOF may be varied based on hydraulic pressures included within electrohydraulic (EH) actuation system utilized to animate movable implements, such as moveable blades (in the case of, for example dozers and motor graders) and implements attached to boom assemblies (in the case of, for example, excavators, feller bunchers, tractors equipped with front end loader (FEL) attachments, wheel loaders, backhoes, and excavators). In still other embodiments, the MRF resistance force and joystick stiffness may be varied as a function of other loads placed on a work vehicle, such as the load placed on the primary engine of a work vehicle. In such embodiments, the controller architecture may progressively increase the MRF resistance force inhibiting joystick movement as the monitored parameter increases, provide tactile cues (e.g., an MRF-applied feel detent or pulsating effect) when a monitored parameter surpasses a preset threshold, and/or otherwise manipulate the MRF resistance force to provide tactile feedback indicative of the monitored parameter.
In further embodiments, the work vehicle MRF joystick system may vary the MRF resistance force to emulate legacy mechanical control schemes in which a joystick is mechanically linked to an actuated component of the work vehicle, such as a pilot valve included in an EH actuation system. For example, in certain implementations, the controller architecture may utilize sensor data to monitor the pressure conditions or valve positions of an EH actuation system and generate certain resistance effects (e.g., a brief pulse of resistance or feel detent) simulating the tactile feedback inherently provided by legacy systems in which a mechanical connection is provided between an actuated component, such as a pilot valve, and a joystick device. This, in turn, may provide an operator with familiar tactile cues regarding the operational status of the EH system (e.g., when pilot valve lift-off or cracking occurs) in the context of an EH control scheme as opposed to a purely mechanical joystick control scheme. Stated differently, the controller architecture may command the MRF joystick resistance mechanism to selectively vary the MRF resistance force in a manner providing tactile feedback indicating when the pilot valve initially opens during usage of the EH actuation system.
In still other embodiments, the MRF joystick system may vary the MRF resistance force impeding joystick motion as a function of a current monitored machine parameter, such as a current steering angle or ground speed, relative to an operator input command received via a joystick device. As a more specific example, embodiments of the MRF joystick system may progressively increase the MRF resistance force or joystick stiffness to should an operator attempt to rotate (or otherwise move) a joystick in a manner that, if allowed to continue unimpeded, would result in an abrupt change in work vehicle motion. Examples of such work vehicle motions (any or all of which may be controlled utilizing a joystick in embodiments) include work vehicle heading or steering angle, work vehicle ground speed, and movement of a boom-mounted implement. Such an approach of increasing the MRF resistance force inhibiting joystick motion when joystick inputs would result in abrupt work vehicle motions is referred to herein as “trajectory shaping,” as discussed more fully below. Trajectory shaping by selective variations in joystick stiffness may encourage operator joystick movements bringing about relatively seamless or smooth transitions in work vehicle motions. Additionally, such an approach allows operator intent to be confirmed, in passive sense, when an operator exerts sufficient force on the joystick to overcome the increased MRF resistance force to, for example, abruptly change the steering angle or ground speed of the work vehicle.
As indicated above, embodiments of the work vehicle MRF joystick system can also provide a relatively high degree of customization flexibility by, for example, enabling the below-described MRF resistance effects to be tailored to operator preference. In this regard, an operator may be permitted to adjust the intensity of the MRF resistance effect to preference in embodiments; or, perhaps, to selectively activate or deactivate a given MRF resistance effect altogether. In other instances, the MRF joystick system may permit an operator to program the MRF resistance effects by, for example, selecting the particular monitored parameter or parameters upon joystick stiffness is varied. Such personalization or customization settings may be stored in memory and associated with a particular operator in embodiments. Upon work vehicle startup, or at another appropriate juncture during work vehicle operation, the MRF customization settings may then be recalled based upon the identity of the current operator (e.g., as determined by entry of an operator-specific pin when first logging into the work vehicle or as otherwise ascertained) and then applied as appropriate.
An example embodiment of a work vehicle MRF joystick system will now be described in conjunction with
Referring initially to
The hydraulic cylinders 38, 40, 42 are included in an electrohydraulic (EH) actuation system 44, which is encompassed by a box 46 entitled “actuators for joystick-controlled functions” in
As schematically illustrated in an upper left portion of
As schematically illustrated in
An MRF joystick resistance mechanism 56 is at least partially integrated into the base housing 62 of the MRF joystick device 52. The MRF joystick resistance mechanism 56 (and the other MRF joystick resistance mechanisms mentioned in this document) may also alternatively be referred to as an “MRF damper,” as an “MRF brake device,” or as simply an “MRF device” or “MRF mechanism.” The MRF joystick resistance mechanism 56 can be controlled to adjust the MRF resistance force and, therefore, joystick stiffness resisting joystick motion relative to the base housing 62 in at least one DOF. During operation of the MRF joystick system 22, the controller architecture 50 may selectively command the MRF joystick resistance mechanism 56 to increase the joystick stiffness impeding joystick rotation about a particular axis or combination of axes. As discussed more fully below, the controller architecture 50 may command the MRF joystick resistance mechanism 56 to increase joystick stiffness, when appropriate to perform any one of a number of enhanced joystick functionalities, by increasing the strength of an EM field in which a magnetorheological fluid contained in the MRF joystick resistance mechanism 56 is at least partially immersed. A generalized example of one manner in which the MRF joystick resistance mechanism 56 may be realized is described below in connection with
The excavator 20 is further equipped with any number of onboard sensors 70. Such sensors 70 may include sensors contained in an obstacle detection system, which may be integrated into the excavator 20 in embodiments. The non-joystick input sensors 70 may further include any number and type of boom assembly sensors 72, such as boom assembly tracking sensors suitable for tracking the position and movement of the excavator boom assembly 24. Such sensors can include rotary or linear variable displacement transducers integrated into excavator boom assembly 24 in embodiments. For example, in one possible implementation, rotary position sensors may be integrated into the pivot joints of the boom assembly 24; and the angular displacement readings captured by the rotary position sensors, taken in conjunction with known dimensions of the boom assembly 24 (as recalled from the memory 48), may be utilized to track the posture and position of the boom assembly 24 (including the bucket 26) in three dimensional space. In other instances, the extension and reaction of the hydraulic cylinders 38, 40, 42 may be measured (e.g., utilizing linear variable displacement transducers) and utilized to calculate the current posture and positioning of the excavator boom assembly 24. Other sensor inputs can also be considered by the controller architecture 50 in addition or lieu of the aforementioned sensor readings, such as inertia-based sensor readings; e.g., as captured by inertia sensors, such as MEMS gyroscopes, accelerometers, and possibly magnetometers packaged as IMUs, which are affixed to the excavator 20 at various locations. For example, IMUs can be affixed to the excavator chassis 28 and one or more locations (different linkages) of the excavator boom assembly 24. Vision systems capable of tracking of the excavation implement or performing other functions related to the operation of the excavator 20 may also be included in the onboard board sensors 70 when useful in performing the functions described below.
One or more load measurement sensors, such as weight- or strain-based sensors (e.g., load cells), may further be included in the non joystick sensor inputs 70 in at least some implementations of the work vehicle MRF joystick system 22. In embodiments, such load measurement sensors may be utilized to directly measure the load carried by the bucket 26 (generally, a “load-moving implement” or “load-carrying implement”) at any given time during excavator operation. The load measurement sensors can also measure other parameters (e.g., one or more hydraulic pressures within the EH actuation system 44) indicative of the load carried by the boom assembly 24 in embodiments. In other realizations, the MRF joystick system 22 may be integrated into a work vehicle having a bed or tank for transporting a material, such as the bed of an articulated dump truck. In this latter case, the load measurement sensors included in the sensors 70 may assume the form of payload weighing sensors capable of weighing or approximating the weight of material carried within the bed or tank of the work vehicle at any particular juncture in time.
In embodiments, the work vehicle sensors 70 may further include a number of vehicle motion data sources 74. The vehicle motion data sources 74 can include any sensors or data sources providing information pertaining to changes in the position, speed, heading, or orientation of the excavator 20. Again, MEMS gyroscopes, accelerometers, and possibly magnetometers packaged IMUs can be utilized to detect and measure such changes. Inclinometers or similar sensors may be employed to monitor the orientation of the excavator chassis 28 or portions of the boom assembly 24 relative to gravity in embodiments. The vehicle motion data sources 74 may further include Global Navigation Satellite System (GNSS) modules, such as Global Positioning System (GPS) modules, for monitoring excavator position and motion states. In embodiments, the vehicle motion data sources 74 may also include sensors from which the rotational rate of the undercarriage tracks may be calculated, electronic compasses for monitoring heading, and other such sensors. The vehicle motion data sources 74 can also include various sensors for monitoring the motion and position of the boom assembly 24 and the bucket 26, including MEMS devices integrated into the boom assembly 24 (as previously noted), transducers for measuring angular displacements at the pin joints of the boom assembly, transducers for measuring the stroke of the hydraulic cylinders 38, 40, 42, and the like.
Embodiments of the MRF joystick system 22 may further include any number of other non-joystick components 76 in addition to those previously described. Such additional non-joystick components 76 may include an operator interface 78 (distinct from the MRF joystick device 52), a display device 80 located in the excavator cabin 32, and various other types of non-joystick sensors 82. The operator interface 78, in particular, can include any number and type of non joystick input devices for receiving operator input, such as buttons, switches, knobs, and similar manual inputs external to the MRF joystick device 52. Such input devices included in the operator interface 78 can also include cursor-type input devices, such as a trackball or joystick, for interacting with a graphical user interface (GUI) generated on the display device 80. The display device 80 may be located within the cabin 32 and may assume the form of any image-generating device on which visual alerts and other information may be visually presented. The display device 80 may also generate a GUI for receiving operator input or may include other inputs (e.g., buttons or switches) for receiving operator input, which may be pertinent to the controller architecture 50 when performing the below-described processes. In certain instances, the display device 80 may also have touch input capabilities.
Finally, the MRF joystick system 22 can include various other non-joystick sensors 82, which provide the controller architecture 50 with data inputs utilized in carrying-out the below-described processes. For example, the non-joystick sensors 82 can include sensors for automatically determining the type of implement currently attached to the excavator 20 (or other work vehicle) in at least some implementations when this information is considered by the controller architecture 50 in determining when to increase joystick stiffness to perform certain enhanced joystick functions described herein; e.g., such sensors 82 may determine a particular implement type currently attached to the excavator 20 by sensing a tag (e.g., a radio frequency identification tag) or reading other identifying information present on the implement, by visual analysis of a camera feed capturing the implement, or utilizing any other technique. In other instances, an operator may simply enter information selecting the implement type currently attached to the boom assembly 24 by, for example, interacting with a GUI generated on the display device 80. In still other instances, such other non-joystick sensors 82 may include sensors or cameras capable of determining when an operator grasps or other contacts the joystick 60. In other embodiments, such sensors may not be contained in the MRF joystick system 22.
As further schematically depicted in
Discussing the joystick configuration or layout of the excavator 20 in greater detail, the number of joystick devices included in the MRF joystick system 22, and the structural aspects and function of such joysticks, will vary amongst embodiments. As previously mentioned, although only a single joystick device 52 is schematically shown in
Different control schemes can be utilized to translate movement of the joysticks 60 included in the joystick devices 52, 54 to corresponding movement of the excavator boom assembly 24. In many instances, the excavator 20 will support boom assembly control in either (and often allow switching between) a “backhoe control” or “SAE control” pattern and an “International Standard Organization” or “ISO” control pattern. In the case of the backhoe control pattern, movement of the left joystick 60 to the operator's left (arrow 94) swings the excavator boom assembly 24 in a leftward direction (corresponding to counter-clockwise rotation of the chassis 28 relative to the tracked undercarriage 30), movement of the left joystick 60 to the operator's right (arrow 96) swings the boom assembly 24 in a rightward direction (corresponding to clockwise rotation of the chassis 28 relative to the tracked undercarriage 30), movement of the left joystick 60 in a forward direction (arrow 98) lowers the hoist boom 34, and movement of the left joystick 60 in an aft or rearward direction (arrow 100) raises the hoist boom 34. Also, in the case of the backhoe control pattern, movement of the right joystick 60 to the left (arrow 102) curls the bucket 26 inwardly, movement of the right joystick 60 to the right (arrow 104) uncurls or “opens” the bucket 26, movement of the right joystick 60 in a forward direction (arrow 106) rotates the dipperstick 36 outwardly, and movement of the right joystick 60 in an aft or rearward direction (arrow 108) rotates the dipperstick 36 inwardly. Comparatively, in the case of an ISO control pattern, the joystick motions for the swing commands and the bucket curl commands are unchanged, while the joystick mappings of the hoist boom and dipperstick are reversed. Thus, in the ISO control pattern, forward and aft movement of the left joystick 60 controls the dipperstick rotation in the previously described manner, while forward and aft movement of the right joystick 60 controls motion (raising and lowering) of the hoist boom 34 in the manner described above.
Turning now to
Referring now to the example joystick construction shown in
The joystick 60 of the MRF joystick device 52 further includes a stinger or lower joystick extension 120, which projects from the generally spherical base 112 in a direction opposite the joystick handle 110. The lower joystick extension 120 is coupled to a static attachment point of the base housing 62 by a single centering or return spring 124 in the illustrated schematic; here noting that such an arrangement is simplified for the purposes of illustration and more complex spring return arrangements (or other joystick biasing mechanisms, if present) will typically be employed in actual embodiments of the MRF joystick device 52. When the joystick 60 is displaced from the neutral or home position shown in
The example MRF joystick resistance mechanism 56 includes a first and second MRF cylinders 126, 128 shown in
The MRF cylinders 126, 128 each include a cylinder body 134 to which a piston 138, 140 is slidably mounted. Each cylinder body 134 contains a cylindrical cavity or bore 136 in which a head 138 of one of the pistons 138, 140 is mounted for translational movement along the longitudinal axis or centerline of the cylinder body 134. About its outer periphery, each piston head 138 is fitted with one or more dynamic seals (e.g., O-rings) to sealingly engaging the interior surfaces of the cylinder body 134, thereby separating the bore 136 into two antagonistic variable-volume hydraulic chambers. The pistons 138, 140 also each include an elongated piston rod 140, which projects from the piston head 138 toward the lower joystick extension 120 of the joystick 60. The piston rod 140 extends through an end cap 142 affixed over the open end of the cylinder body 134 (again, engaging any number of seals) for attachment to the lower joystick extension 120 at a joystick attachment point 144. In the illustrated example, the joystick attachment points 144 assume the form of pin or pivot joints; however, in other embodiments, more complex joints (e.g., spherical joints) may be employed to form this mechanical coupling. Opposite the joystick attachment points 144, the opposing end of the MRF cylinders 126, 128 are mounted to the respective static attachment points 130, 132 via spherical joints 145. Finally, hydraulic ports 146, 148 are further provided in opposing end portions of each MRF cylinder 126, 128 to allow the inflow and outflow of magnetorheological fluid in conjunction with translational movement or stroking of the pistons 138, 140 along the respective longitudinal axes of the MRF cylinders 126, 128.
The MRF cylinders 126, 128 are fluidly interconnected with corresponding MRF values 150, 152, respectively, via flow line connections 178, 180. As is the case with the MRF cylinders 126, 128, the MRF valves 150, 152 are presented as identical in the illustrated example, but may vary in further implementations. Although referred to as “valves” by common terminology (considering, in particular, that the MRF valves 150, 152 function to control magnetorheological fluid flow), it will be observed that the MRF valves 150, 152 lack valve elements and other moving mechanical parts in the instant example. As a beneficial corollary, the MRF valves 150, 152 provide fail safe operation in that, in the unlikely event of MRF valve failure, magnetorheological fluid flow is still permitted through the MRF valves 150, 152 with relatively little resistance. Consequently, should either or both of the MRF valves 150, 152 fail for any reason, the ability of MRF joystick resistance mechanism 56 to apply resistance forces restricting or impeding joystick motion may be compromised; however, the joystick 60 will remain freely rotatable about the X- and Y-axes in a manner similar to a traditional, non-MRF joystick system, and the MRF joystick device 52 will remain capable of controlling the excavator boom assembly 24 as typical.
In the depicted embodiment, the MRF valves 150, 152 each include a valve housing 154, which contains end caps 156 affixed over opposing ends of an elongated cylinder core 158. A generally annular or tubular flow passage 160 extends around the cylinder core 158 and between two fluid ports 162, 164, which are provided through the opposing end caps 156. The annular flow passage 160 is surrounded by (extends through) a number of EM inductor coils 166 (hereafter, “EM coils 166”), which are wound around paramagnetic holders 168 and interspersed with a number of axially- or longitudinally-spaced ferrite rings 170. A tubular shroud 172 surrounds this assembly, while a number of leads are provided through the shroud 172 to facilitate electrical interconnection with the housed EM coils 166. Two such leads, and the corresponding electrical connections to a power supply and control source 177, are schematically represented in
The fluid ports 162, 164 of the MRF valves 150, 152 are fluidly connected to the ports 146, 148 of the corresponding the MRF cylinders 126, 128 by the above-mentioned conduits 178, 180, respectively. The conduits 178, 180 may be, for example, lengths of flexible tubing having sufficient slack to accommodate any movement of the MRF cylinders 126, 128 occurring in conjunction with rotation of the joystick 60. Consider, in this regard, the example scenario of
Given the responsiveness of MRF joystick resistance mechanism 56, the controller architecture 50 can control the MRF joystick resistance mechanism 56 to only briefly apply such an MRF resistance force, to increase the strength of the MRF resistance force in a predefined manner (e.g., in a gradual or stepped manner) with increasing piston displacement, or to provide various other resistance effects (e.g., a tactile detent or pulsating effect), as discussed in detail below. The controller architecture 50 can likewise control the MRF joystick resistance mechanism 56 to selectively provided such resistance effects as the piston 138, 140 included in the MRF valve 150 strokes in conjunction with rotation of the joystick 60 about the X-axis of coordinate legend 118. Moreover, the MRF joystick resistance mechanism 56 may be capable of independently varying the EM field strength generated by the EM coils 166 within the MRF valves 150, 152 to allow independent control of the MRF resistance forces impeding joystick rotation about the X- and Y-axes of coordinate legend 118.
The MRF joystick device 52 may further contain one or more joystick position sensors 182, 184 (e.g., optical or non-optical sensors or transformers) for monitoring the position or movement of the joystick 60 relative to the base housing 62. In the illustrated example, specifically, the MRF joystick device 52 includes a first joystick position sensor 182 (
As previously emphasized, the above-described embodiment of the MRF joystick device 52 is provided by way of non-limiting example only. In alternative implementations, the construction of the joystick 60 can differ in various respects. So too may the MRF joystick resistance mechanism 56 differ in further embodiments relative to the example shown in
In still other implementations, the design of the MRF joystick device may permit the magnetorheological fluid to envelop and act directly upon a lower portion of the joystick 60 itself, such as the spherical base 112 in the case of the joystick 60, with EM coils positioned around the lower portion of the joystick and surrounding the magnetological fluid body. In such embodiments, the spherical base 112 may be provided with ribs, grooves, or similar topological features to promote displacement of the magnetorheological fluid in conjunction with joystick rotation, with energization of the EM coils increasing the viscosity of the magnetorheological fluid to impede fluid flow through restricted flow passages provided about the spherical base 112 or, perhaps, due to sheering of the magnetorheological fluid in conjunction with joystick rotation. Various other designs are also possible in further embodiments of the MRF joystick system 22.
Regardless of the particular design of the MRF joystick resistance mechanism 56, the usage of MRF technology to selectively generate a variable MRF resistance force or joystick stiffness impeding (resisting or preventing) targeted joystick motions provides several advantages. As a primary advantage, the MRF joystick resistance mechanism 56 (and MRF joystick resistance mechanism generally) are highly responsive and can effectuate desired changes in EM field strength, in the rheology of the magnetorheological fluid, and ultimately in the MRF-applied joystick stiffness impeding joystick motions in highly abbreviated time periods; e.g., time periods on the order of 1 millisecond in certain instances. Correspondingly, the MRF joystick resistance mechanism 56 may enable the MRF resistance force to be removed (or at least greatly reduced) with an equal rapidity by quickly reducing current flow through the EM coils and allowing the rheology of the magnetorheological fluid (e.g., fluid viscosity) to revert to its normal, unstimulated state. The controller architecture 50 can further control the MRF joystick resistance mechanism 56 to generate the MRF resistance force to have a continuous range of strengths or intensities, within limits, through corresponding changes in the strength of the EM field generated utilizing the EM coils 166. Beneficially, the MRF joystick resistance mechanism 56 can provide reliable, essentially noiseless operation over extended time periods. Additionally, the magnetorheological fluid can be formulated to be non-toxic in nature, such as when the magnetorheological fluid contains carbonyl iron-based particles dispersed in an alcohol-based or oil-based carrier fluid, as previously described. Finally, as a still further advantage, the above-described configuration of the MRF joystick resistance mechanism 56 allows the MRF joystick system 22 to selectively generate a first resistance force or joystick stiffness deterring joystick rotation about a first axis (e.g., the X-axis of coordinate legend 118 in
Advancing next to
The MRF machine state feedback process 190 commences at STEP 192 in response to the occurrence of a predetermined trigger event. In embodiments, the trigger event can be startup of a work vehicle (e.g., the excavator 20 shown in
Following commencement of the MRF machine state feedback process 190, the controller architecture 50 progresses to STEP 194 and collects the pertinent data inputs subsequently utilized to determine the appropriate variations in the MRF resistance force or forces resisting joystick motion in one or more DOFs. The particular data inputs gathered during STEP 194 will vary in relation to the parameter or parameters correlated to the variable joystick stiffness, as discussed more fully below in connection with STEPS 204, 206 of the MRF machine state feedback process 190. Generally, iterations of the process 190 may be performed at a relatively rapid rate such that the data inputs collected during STEP 194 may reflect real-time or near real-time data provided by one or more sensors onboard the work vehicle, such as any of the sensors 70 of the above-described example excavator 20. Stored data may also be recalled from memory (e.g., the memory 48 shown in
Next, at STEP 196 of the MRF machine state feedback process 190, the controller architecture 50 receives data indicative of the current joystick movement and position of the MRF joystick device (or devices) under consideration. In the case of the example excavator 20, the controller architecture 50 receives data from the joystick position sensors 182, 184 contained in the MRF joystick devices 52, 54 regarding the movement of the respective joysticks 60 included in the devices 52, 54. Such data enables the controller architecture 50 to rapidly increase or decrease the MRF resistance force inhibiting joystick movement (e.g., joystick rotation about a particular axis) in correlation to the current joystick position and movement characteristics. This, in turn, enables the MRF resistance force to progressively increase, to progressively decrease, to be quickly applied, or to be quickly removed, as needed, to generate the desired MRF resistance effects.
Progressing to STEP 202 of the MRF machine state feedback process 190, the controller architecture 50 determines whether joystick position or the monitored machine state correlated to joystick stiffness has changed in a manner warranting variations in the currently-applied MRF resistance force and, therefore, the joystick stiffness resisting joystick motion in a particular direction. If this is the case, the controller architecture 50 progresses to STEP 204 of the MRF machine state feedback process 190, as further described below. Otherwise, the controller architecture 50 advances to STEP 200 and determines whether the current iteration of the MRF machine state feedback process 190 should terminate; e.g., due to work vehicle shutdown, due to continued inactivity of the joystick-controlled function for a predetermined time period, or due to removal of the condition or trigger event in response to which the process 190 initially commenced. If determining that the MRF machine state feedback process 190 should terminate at STEP 200, the controller architecture 50 progresses to STEP 202 of the process 190, the MRF machine state feedback process 190 terminates accordingly. If instead determining that the process 190 should continue, the controller architecture 50 returns to STEP 194 and the above-described process steps repeat.
As previously indicated, the controller architecture 50 advances to STEP 204 when determining that joystick position or the monitored machine state correlated to MRF joystick stiffness has changed based upon the data inputs collected during STEPS 194, 196 of the MRF machine state feedback process 190. During STEP 204, the controller architecture 50 determines the appropriate manner in which to vary the MRF resistance force to achieve a desired joystick stiffness indicative of the monitored machine state or parameter. The controller architecture 50 then advances to STEP 206 and applies the newly-determined MRF resistance force by transmitting appropriate commands to the MRF joystick resistance mechanism 56 to vary the rheology (viscosity) of the MRF fluid body (or bodies) in a manner achieving the desired resistance effect. As discussed throughout this document, such effects are correlated to joystick position and, thus, may be temporarily applied to generate detent effects or pulsating effects; the MRF resistance force may be progressively increased or otherwise varied to substantially match increases in a monitored parameter (e.g., a ground speed, a component position, a load, or a hydraulic pressure of the work vehicle); or the MRF resistance force may be lessened or removed when appropriate based upon joystick movement and the state of the monitored parameter. After application of the determined adjustments to the MRF resistance force inhibiting joystick motion in at least one DOF, the controller architecture 50 then progresses to STEP 200 and determines whether the current iteration of the MRF machine state feedback process 190 should terminate, as previously discussed. In this manner, the controller architecture 50 may repeatedly perform iterations of the process 190 to actively vary the MRF resistance force impeding or resisting joystick motion in at least one DOF, such as joystick rotation about one or more axes, to provide a work vehicle operator with tactile feedback indicative of a monitored parameter pertaining to work vehicle as the operator interacts with a MRF joystick device, such as MRF joystick device 52 discussed above in connection with
Discussing now STEP 204 of the MRF machine state feedback process 190 in greater detail, several example machine state parameters 208, 210, 212, 214, 215 are identified for which the MRF joystick system 22 may provide tactile feedback via selectively variations in the MRF stiffness force or forces resisting joystick movement. The illustrated machine state parameters 208, 210, 212, 214, 215 are provided by way of non-limiting example only and are each described, in turn, below. Initially addressing the parameter entitled “work vehicle load” (parameter 208,
In embodiments, the monitored work vehicle load may be any variable force resisting movement of a component of the work vehicle in some manner. For example, the monitored load may be the mass or weight of a material weight borne by load-carrying component of the work vehicle; the term “load-carrying component” encompassing buckets, grapples, bale spears, feller heads, lifts, and other such tools or implements commonly attached to work vehicles and utilized to transport materials or objects from one location to another. Such load forces resisting movement of a movable implement may also forces encountered during excavation operations as, for example, hardened regions of earth or other difficult-to-displace regions are encountered by a tool (e.g., a trencher, a hydraulic hammer, or a bucket). In each of these scenarios, the controller architecture 50 may estimate the load resisting implement movement in any given direction or combination of directions and then command the MRF joystick resistance mechanism 56 to vary the MRF resistance force accordingly; e.g., such that the MRF resistance force inhibiting joystick movement increases in conjunction with increases in the force resisting implement movement in a given direction. Similarly, in embodiments in which the work vehicle comprises a load-carrying receptacle, such as a bucket, tank, or bed, the MRF joystick system may increase the MRF resistance force with as the weight of the material held within the load-carrying receptacle (herein, the “fill weight”) increases. Such increases the MRF resistance force may be implemented in a stepwise fashion or, instead, in a substantially continual fashion (over a given resistance range) such that, for example, the MRF resistance force progressively increases in substantial portion to increases in the monitored load. In other implementations, different MRF-applied tactile cues (e.g., feel detents) may be generated when a load placed on the work vehicle surpasses or becomes equivalent to a predetermined threshold, such as in the case of the below-described tipoff assist function.
The above-described variations in the MRF resistance force can be axis-specific or direction-specific in embodiments in which the MRF joystick device is capable of rotational about perpendicular axes, such as in the case of the joystick device 52 shown in
In embodiments in which the work vehicle includes an EH actuation system, the MRF joystick system may increase the MRF resistance force in conjunction with variations in a circuit pressure within the EH actuation system. For example, with respect to the example excavator 20 discussed above in connection with
In further implementations, the MRF joystick system 22 may vary the MRF resistance force impeding joystick movement in at least one direction as a function of another type of load placed on the work vehicle, such as a current load placed on the primary (e.g., internal combustion) engine of a work vehicle engine. Additionally, while the previous description principally focuses on altering the MRF resistance force based upon variations on monitored work vehicle loads considered in isolation or an independent sense, further embodiments of the MRF joystick system 22 may adjust the MRF resistance force based upon changes in load (or another monitored work vehicle parameter mentioned herein) relative to another parameter or threshold value. For example, in certain embodiments, the controller architecture 50 may compare a monitored load to a predetermined threshold value (e.g., a particular minimum load value stored in the memory 48) and implement the above-described MRF resistance force modifications only after a currently monitored load surpasses the threshold value. A similar approach may be utilized to assist operators in piloting a work vehicle to bring a load, such as the fill weight of a bucket, to a desired value, as in the case of a tipoff assist or control function described in the following paragraph.
Embodiments of the MRF joystick system 22 may monitor a current fill weight of an end effector or load-carrying implement and vary the MRF resistance force based of a differential between a target tipoff weight and the current fill weight of the implement, task. In this regard, certain work vehicle, such as wheel loaders, excavators, and similar work vehicle equipped with fillable buckets, may be provided with a tipoff control function, which assists an operator in utilizing the work vehicle to fill a receptacle (e.g., a bed of a dump truck) with a desired quantity of material. In this case, the MRF joystick system may estimate the amount of material (e.g., by weight) utilizing any of the methods described herein (e.g., using a strain gauge, a load sensor, or any number of pressure sensors) and then utilize this information in determining the manner in which to apply variances in the MRF joystick stiffness, thereby communicating to the operator that an appropriate amount of material is within the bucket to satisfy the established weight target of the dump truck (or other receptacle). With respect to the example excavator 20, in particular, the controller architecture 50 may first establish a target tipoff weight to which the bucket 26 is desirably filled; e.g., by recalling from memory 48 a default setting or a setting entered into the excavator computer via operator interface 78. The controller architecture 50 may then selectively vary the MRF resistance force based of a differential between the target tipoff weight and the current fill weight of the bucket 26, as previously described. Such an MRF joystick response may be generated when first filling the bucket 26 (e.g., by increasing joystick stiffness, by providing a detent effect, or by providing pulsating effect) when a target bucket load is achieved. In other instances, the MRF joystick system may provide similar tactile cues assisting an operator with dumping-out an appropriate amount of material to satisfy the target bucket load if the bucket 26 is inadvertently over-filled by the operator when piloting the work vehicle.
With continued reference to STEP 204 of the example MRF machine state feedback process 190 (
In still further implementations of the work vehicle MRF joystick system 22, and as indicated in
In still embodiments of the work vehicle MRF joystick system 22, and as indicated by the example parameter 214 at STEP 204 of the MRF machine state feedback process 190 (
In still further embodiments, the MRF joystick system 22 may selectively vary the MRF resistance force inhibiting joystick motion in at least one DOF in a manner mimicking legacy systems familiar to operators, as indicated by parameter 215 listed in STEP 204 of the MRF machine state feedback process 190 (
In the above-described manner, embodiments of the MRF joystick system 22 may provide operators with tactile feedback indicative of current machine states or parameters through selective increases in the MRF resistance force impeding joystick movement in at least one DOF. Such feedback is provided to an operator interacting with the above-described MRF joystick devices in a highly intuitive and rapid manner. Further benefits are achieved through the usage of MRF technology itself as opposed to the usage of other resistance mechanisms, such as actuated friction or brake mechanisms, also capable of selectively impeding joystick motion when returning to a centered position after displacement therefrom. Such benefits may include highly abbreviated response times; minimal frictional losses in the absence of MRF-applied resistance forces; reliable, essentially noiseless operation; and other benefits as further discussed below. Additionally, embodiments of the below-described MRF joystick resistance mechanism may be capable of generate a continuous range of resistance forces over a resistance force range in relatively precise manner and in accordance with commands or control signals issued by the controller architecture 50. While the foregoing description principally focuses on a particular type of work vehicle (an excavator) including a particular joystick-controlled work vehicle function (boom assembly movement), embodiments of the MRF joystick system 22 described herein are amenable to integration into a wide range of work vehicles, as further discussed below in connection with
Turning now to
In each of the above-mentioned examples, the MRF joystick devices can be controlled to provide machine state feedback through intelligent MRF-applied variations in joystick stiffness. In this regard, any or all of the example wheeled loader 216, the SSL 218, and the motor grader 220 can be equipped with a work vehicle MRF joystick system including at least one joystick device, an MRF joystick resistance mechanism, and a controller architecture. Finally, still further examples of work vehicles usefully equipped with embodiments of the MRF joystick systems described herein are illustrated in a bottom portion of
The following examples of the work vehicle MRF joystick system are further provided and numbered for ease of reference.
1. In embodiments, a work vehicle MRF joystick system includes a joystick device, an MRF joystick resistance mechanism, a controller architecture, and a work vehicle sensor configured to provide sensor data indicative of an operational parameter pertaining to work vehicle. The joystick device includes, in turn, a base housing, a joystick movably mounted to the base housing, and a joystick position sensor configured to monitor movement of the joystick relative to the base housing. The MRF joystick resistance mechanism is controllable to vary an MRF resistance force resisting movement of the joystick relative to the base housing in at least one degree of freedom. Coupled to the joystick position sensor, to the work vehicle sensor, and to the MRF joystick resistance mechanism, the controller architecture is configured to: (i) monitor for variations in the operational parameter utilizing the sensor data; and (ii) provide tactile feedback through the joystick device indicative of the operational parameter by selectively commanding the MRF joystick resistance mechanism to adjust the MRF resistance force impeding joystick movement based, at least in part, on variations in the operational parameter.
2. The work vehicle MRF joystick system of example 1, wherein the operational parameter is a hydraulic load placed on the work vehicle, while the controller architecture is configured to command the MRF joystick resistance mechanism to selectively increase the MRF resistance force with as the hydraulic load increases.
3. The work vehicle MRF joystick system of example 1, wherein the work vehicle includes an EH actuation system and an implement movable utilizing the EH actuation system, the operational parameter is a circuit pressure of the EH actuation system, and the work vehicle sensor includes a pressure sensor configured to monitor the circuit pressure.
4. The work vehicle MRF joystick system of example 1, wherein the work vehicle includes a load-carrying component, the operational parameter is a material weight borne by load-carrying component, and the controller architecture is configured to command the MRF joystick resistance mechanism to selectively increase the MRF resistance force with as the material weight increases.
5. The work vehicle MRF joystick system of example 4, wherein the load-carrying component of the work vehicle includes a boom-mounted implement, while the controller architecture is configured to increase the MRF resistance force in a manner impeding joystick movements raising the boom-mounted implement.
6. The work vehicle MRF joystick system of example 4, wherein the load-carrying component includes a receptacle of the work vehicle, while the operational parameter is a payload weight held by the receptacle.
7. The work vehicle MRF joystick system of example 1, wherein the work vehicle includes a bucket, and the work vehicle sensor is configured to monitor a current fill weight of the bucket. The controller architecture is configured to: (i) establish a target tipoff weight to which the bucket is desirably filled, and (ii) selectively vary the MRF resistance force based of a differential between the target tipoff weight and the current fill weight of the bucket.
8. The work vehicle MRF joystick system of example 1, wherein the operational parameter is a ground speed of the work vehicle, while the controller architecture is configured to command the MRF joystick resistance mechanism to selectively increase the MRF resistance force with as the ground speed of the work vehicle increases.
9. The work vehicle MRF joystick system of example 8, wherein the MRF resistance force impedes joystick movement controlling at least one of work vehicle heading and work vehicle ground speed.
10. The work vehicle MRF joystick system of example 1, wherein the work vehicle includes a movable component having motion stop point, the operational parameter is displacement of the movable component relative to the motion stop point, and the controller architecture is configured to command the MRF joystick resistance mechanism to selectively increase the MRF resistance force as the movable component approaches the motion stop point.
11. The work vehicle MRF joystick system of example 10, wherein the movable component includes a hydraulic cylinder having a stroke limit or an articulable joint of a boom assembly.
12. The work vehicle MRF joystick system of example 1, wherein the work vehicle includes an EH actuation system containing a pilot valve, while the controller architecture is configured to command the MRF joystick resistance mechanism to selectively vary the MRF resistance force in a manner providing tactile feedback indicating when the pilot valve initially opens.
13. The work vehicle MRF joystick system of example 1, wherein the joystick device is utilized to control movement of the work vehicle, and the operational parameter is a current motion state of the work vehicle. The controller architecture is configured to: (i) determine when motion of the joystick in an operator input direction at a detected rate will result in an undesirably abrupt change in the current motion state of the work vehicle; and (ii) when determining when motion of the joystick in an operator input direction at a detected rate will result in an undesirably abrupt change in the current motion state of the work vehicle, command the MRF joystick resistance mechanism to increase the MRF resistance force to impede continued movement of the joystick in the operator input direction.
14. The work vehicle MRF joystick system of example 13, wherein the joystick device is utilized to control at least one of a ground speed of the work vehicle and a heading of the work vehicle.
15. The work vehicle MRF joystick system of example 13, wherein the work vehicle includes boom assembly attached to a chassis of the work vehicle, while the joystick device is utilized to control movement of the boom assembly.
CONCLUSIONThe foregoing has thus provided work vehicle MRF joystick systems configured to provide machine state feedback through variations in MRF resistance force. Such parameters can include, for example, various loads applied to the work vehicle, ground speed of the work vehicle, and proximity of movable work vehicle component to motion stops. Further, in some embodiments, the MRF joystick system may vary an MRF resistance force impeding joystick motion in a manner simulating legacy systems in which a mechanical linkage is provided between a joystick and an actuated component, such as a pilot valve. In still other implementations in which the joystick device is utilized to control movement of the work vehicle, such as ground speed, heading, or boom assembly movements, the MRF joystick system may increase the MRF resistance force to discourage (or to confirm operator intent) joystick motions resulting in relatively abrupt changes in the current motion state of the work vehicle. In so doing, embodiments of the MRF joystick systems intuitively provide tactile feedback enhancing operator awareness of key parameters or conditions of the work vehicle to improve operator satisfaction levels, improve efficacy in utilizing the work vehicle to perform various works tasks, and to provide other benefits, such as minimizing component wear in instances in which abrupt changes in work vehicle motion are reduced.
As used herein, the singular forms “a”, “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. Explicitly referenced embodiments herein were chosen and described in order to best explain the principles of the disclosure and their practical application, and to enable others of ordinary skill in the art to understand the disclosure and recognize many alternatives, modifications, and variations on the described example(s). Accordingly, various embodiments and implementations other than those explicitly described are within the scope of the following claims.
Claims
1. A work vehicle magnetorheological fluid (MRF) joystick system utilized onboard a work vehicle, the work vehicle MRF joystick system comprising:
- a joystick device, comprising: a base housing; a joystick movably mounted to the base housing; and a joystick position sensor configured to monitor movement of the joystick relative to the base housing;
- an MRF joystick resistance mechanism controllable to vary an MRF resistance force impeding joystick movement relative to the base housing in at least one degree of freedom;
- a work vehicle sensor configured to provide sensor data indicative of an operational parameter pertaining to work vehicle; and
- a controller architecture coupled to the joystick position sensor, to the MRF joystick resistance mechanism, and to the work vehicle sensor, the controller architecture configured to: monitor for variations in the operational parameter utilizing the sensor data; and provide tactile feedback through the joystick device indicative of the operational parameter by selectively commanding the MRF joystick resistance mechanism to adjust the MRF resistance force based, at least in part, on variations in the operational parameter.
2. The work vehicle MRF joystick system of claim 1, wherein the operational parameter comprises a hydraulic load placed on the work vehicle; and
- wherein the controller architecture is configured to command the MRF joystick resistance mechanism to increase the MRF resistance force as the hydraulic load increases.
3. The work vehicle MRF joystick system of claim 1, wherein the work vehicle comprises an electrohydraulic (EH) actuation system and an implement movable utilizing the EH actuation system;
- wherein the operational parameter comprises a circuit pressure of the EH actuation system; and
- wherein the work vehicle sensor comprises a pressure sensor configured to monitor the circuit pressure.
4. The work vehicle MRF joystick system of claim 1, wherein the work vehicle comprises a load-carrying component;
- wherein the operational parameter comprises a material weight borne by load-carrying component; and
- wherein the controller architecture is configured to command the MRF joystick resistance mechanism to increase the MRF resistance force as the material weight increases.
5. The work vehicle MRF joystick system of claim 4, wherein the load-carrying component of the work vehicle comprises a boom-mounted implement; and
- wherein the controller architecture is configured to increase the MRF resistance force in a manner impeding joystick movements raising the boom-mounted implement.
6. The work vehicle MRF joystick system of claim 4, wherein the load-carrying component comprises a receptacle of the work vehicle; and
- wherein the operational parameter comprises a payload weight held by the receptacle.
7. The work vehicle MRF joystick system of claim 1, wherein the work vehicle comprises a bucket;
- wherein the work vehicle sensor is configured to monitor a current fill weight of the bucket; and
- wherein the controller architecture is configured to: establish a target tipoff weight to which the bucket is desirably filled; and selectively vary the MRF resistance force based of a differential between the target tipoff weight and the current fill weight of the bucket.
8. The work vehicle MRF joystick system of claim 1, wherein the operational parameter comprises a ground speed of the work vehicle; and
- wherein the controller architecture is configured to command the MRF joystick resistance mechanism to increase the MRF resistance force as the ground speed of the work vehicle increases.
9. The work vehicle MRF joystick system of claim 8, wherein the MRF resistance force impedes joystick movement controlling at least one of work vehicle heading and work vehicle ground speed.
10. The work vehicle MRF joystick system of claim 1, wherein the work vehicle comprises a movable component having motion stop point;
- wherein the operational parameter comprises displacement of the movable component relative to the motion stop point; and
- wherein the controller architecture is configured to command the MRF joystick resistance mechanism to selectively increase the MRF resistance force as the movable component approaches the motion stop point.
11. The work vehicle MRF joystick system of claim 10, wherein the movable component comprises a hydraulic cylinder having a stroke limit or an articulable joint of a boom assembly.
12. The work vehicle MRF joystick system of claim 1, wherein the work vehicle comprises an electrohydraulic (EH) actuation system containing a pilot valve; and
- wherein the controller architecture is configured to command the MRF joystick resistance mechanism to selectively vary the MRF resistance force in a manner providing tactile feedback indicating when the pilot valve initially opens.
13. The work vehicle MRF joystick system of claim 1, wherein the joystick device is utilized to control movement of the work vehicle;
- wherein the operational parameter comprises a current motion state of the work vehicle; and
- wherein the controller architecture is configured to: determine when motion of the joystick in an operator input direction at a detected rate will result in an undesirably abrupt change in the current motion state of the work vehicle; and when determining when motion of the joystick in an operator input direction at a detected rate will result in an undesirably abrupt change in the current motion state of the work vehicle, command the MRF joystick resistance mechanism to increase the MRF resistance force to impede continued movement of the joystick in the operator input direction.
14. The work vehicle MRF joystick system of claim 13, wherein the joystick device is utilized to control at least one of a ground speed of the work vehicle and a heading of the work vehicle.
15. The work vehicle MRF joystick system of claim 13, wherein the work vehicle comprises boom assembly attached to a chassis of the work vehicle; and
- wherein the joystick device is utilized to control movement of the boom assembly.
16. A work vehicle magnetorheological fluid (MRF) joystick system utilized onboard a work vehicle, the work vehicle MRF joystick system comprising:
- a joystick device, comprising: a base housing; a joystick movably mounted to the base housing; and a joystick position sensor configured to monitor movement of the joystick relative to the base housing;
- an MRF joystick resistance mechanism controllable to vary an MRF resistance force impeding joystick movement relative to the base housing in at least one degree of freedom; and
- a controller architecture coupled to the joystick position sensor and to the MRF joystick resistance mechanism, the controller architecture configured to: monitor a current ground speed of the work vehicle; and selectively command the MRF joystick resistance mechanism to adjust the MRF resistance force based, at least in part, on the current ground speed of the work vehicle.
17. The work vehicle MRF joystick system of claim 16, wherein the controller architecture is configured to command the MRF joystick resistance mechanism to progressively increase the MRF resistance force impeding joystick rotation about a first axis as the current ground speed of the work vehicle increases.
18. The work vehicle MRF joystick system of claim 17, wherein the joystick device is controllable is steer the work vehicle by rotation of the joystick about the first axis.
19. A work vehicle magnetorheological fluid (MRF) joystick system utilized onboard a work vehicle having a boom-mounted implement, the work vehicle MRF joystick system comprising:
- a joystick device, comprising: a base housing; a joystick movably mounted to the base housing; and a joystick position sensor configured to monitor movement of the joystick relative to the base housing;
- an MRF joystick resistance mechanism controllable to vary an MRF resistance force impeding joystick movement relative to the base housing in at least one degree of freedom; and
- a controller architecture coupled to the joystick position sensor and to the MRF joystick resistance mechanism, the controller architecture configured to: estimate a variable load resisting movement of the boom-mounted implement in at least one direction; and selectively command the MRF joystick resistance mechanism to increase the MRF resistance force as the variable load increases.
20. The work vehicle MRF joystick system of claim 19, wherein the variable load comprises a material weight carried by the boom-mounted implement; and
- wherein the controller architecture is configured to command the MRF joystick resistance mechanism to increase the MRF resistance force in a manner impeding joystick motions raising the boom-mounted implement.
Type: Application
Filed: Jun 30, 2020
Publication Date: Nov 4, 2021
Inventors: Aaron R. Kenkel (East Dubuque, IL), Todd F. Velde (Dubuque, IA), Mark E. Breutzman (Potosi, WI), Jeffrey M. Stenoish (Asbury, IA), Matthew Sbai (Dubuque, IA)
Application Number: 16/916,800