# US 2021/0340726 A1 · Work vehicle magnetorheological fluid joystick systems operable in modified joystick stiffness modes > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0340726 A1 - Document ID: US20210340726A1 - Status: Published application - Kind: A1 - Application number: 17/002,052 - Filed: 2020-08-25 - Published: 2021-11-04 - Earliest claimed: 2020-05-01 - Assignees: Deere & Company - Applicants: Deere & Company - Inventors: Alex R. Vandegrift; Craig Christofferson; Amy K. Jones; Anthony K. Kraft; Brett S. Graham; Christopher R. Benson; Christopher J. Meyer; Kenneth Franck; Mark D. Anderson; Todd F. Velde - Web page: https://patentgrep.com/patent/US20210340726A1 ## CPC - E02F 9/2004: {Control mechanisms, e.g. control levers (control levers per se G05G)} - E02F 9/2012: {Setting the functions of the control levers, e.g. changing assigned functions among operations levers, setting functions dependent on the operator or seat orientation} - E02F 9/2029: {Controlling the position of implements in function of its load, e.g. modifying the attitude of implements in accordance to vehicle speed (control for hydraulic or pneumatic drives E02F9/2203, E02F9/2221 and E02F9/2253 take precedence)} - E02F 9/24: Safety devices {, e.g. for preventing overload (E02F9/226 takes precedence)} - E02F 9/265: {with follow-up actions (e.g. control signals sent to actuate the work tool)} - F15B 13/01: Locking-valves or other detent {i.e. load-holding} devices - F16F 9/535: {Magnetorheological [MR] fluid dampers (springs comprising magnetorheological [MR] elastomers F16F1/361)} - F16F 15/002: {characterised by the control method or circuitry (control of mechanical oscillations per se G05D19/00)} - G05G 1/015: Arrangements for indicating the position of a controlling member (means for continuously detecting pedal position G05G1/38; means for detecting position through tactile feedback G05G5/03) - G05G 5/02: Means preventing undesired movements of a controlling member which can be moved in two or more separate steps or ways, e.g. restricting to a stepwise movement or to a particular sequence of movements (G05G5/28 takes precedence) - G05G 5/03: Means for enhancing the operator's awareness of arrival of the controlling member at a command or datum position; Providing feel, e.g. means for creating a counterforce (arrangements for indicating the position of the controlling member G05G1/015) - G05G 5/05: Means for returning or tending to return controlling members to an inoperative or neutral position, e.g. by providing return springs or resilient end-stops (G05G5/28 takes precedence) - G05G 5/12: for holding members in an indefinite number of positions, e.g. by a toothed quadrant (G05G5/28 takes precedence) - G05G 9/047: the controlling member being movable by hand about orthogonal axes, e.g. joysticks {(for switches H01H25/04)} - G06F 3/016: {Input arrangements with force or tactile feedback as computer generated output to the user} - E02F 3/32: working downwardly and towards the machine, e.g. with backhoes - E02F 3/7609: {Scraper blade mounted forwardly of the tractor on a pair of pivoting arms which are linked to the sides of the tractor, e.g. bulldozers} - E02F 3/7636: {Graders with the scraper blade mounted under the tractor chassis} - E02F 9/2045: {Guiding machines along a predetermined path (for graders E02F3/841; machines for construction of roads E01C19/004)} - E02F 9/261: {Surveying the work-site to be treated} - F16F 2224/045: magnetorheological - G05G 1/04: Controlling members for hand actuation by pivoting movement, e.g. levers - G05G 2009/04707: {with ball joint} - G05G 2009/04718: {with cardan or gimbal type joint} - G05G 2009/04751: {Position sensor for linear movement} - G05G 2009/04766: {providing feel, e.g. indexing means, means to create counterforce} - G05G 2505/00: Means for preventing, limiting or returning the movements of parts of a control mechanism, e.g. locking controlling member - E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00) - F15B: SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR - F16F: SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION - G05G: CONTROL DEVICES OR SYSTEMS INSOFAR AS CHARACTERISED BY MECHANICAL FEATURES ONLY ("Bowden" or like mechanisms F16C1/10; gearings or mechanisms not peculiar to this purpose F16H; speed changing or reversing mechanisms for gearings conveying rotary motion F16H59/00 - F16H63/00) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Embodiments of a work vehicle magnetorheological fluid (MRF) joystick system include a joystick device having a base housing, a joystick movably mounted to the base housing, and a joystick position sensor configured to monitor joystick movement. An MRF joystick resistance mechanism is controllable to vary a joystick stiffness resisting movement of the joystick relative to the base housing, while a controller architecture is coupled to the joystick position sensor and to the MRF joystick resistance mechanism. The controller architecture is configured to: (i) selectively place the work vehicle MRF joystick system in a modified joystick stiffness mode during operation of the work vehicle; and (ii) when the work vehicle MRF joystick system is placed in the modified joystick stiffness mode, command the MRF joystick resistance mechanism to vary the joystick stiffness based, at least in part, on the movement of the joystick relative to the base housing. ## Claims ### Claim 1 A work vehicle magnetorheological fluid (MRF) joystick system for usage 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 a joystick stiffness resisting movement of the joystick 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: selectively place the work vehicle MRF joystick system in a modified joystick stiffness mode during operation of the work vehicle; and when the work vehicle MRF joystick system is placed in the modified joystick stiffness mode, command the MRF joystick resistance mechanism to vary the joystick stiffness based, at least in part, on the movement of the joystick relative to the base housing. ### Claim 2 (depends on 1) The work vehicle MRF joystick system of claim 1, wherein the controller architecture is configured to selectively place the work vehicle MRF joystick system based, at least in part, on a type of work implement attached to the work vehicle. ### Claim 3 (depends on 2) The work vehicle MRF joystick system of claim 2, wherein the type of work implement comprises a multi-function implement having first and second functions; and wherein the controller architecture is configured to command the MRF joystick resistance mechanism to restrict joystick movement to first and second substantially linear tracks when the work vehicle MRF joystick system is placed in the modified joystick stiffness mode, joystick movement along the first and second substantially linear tracks controlling the first and second functions of the multi-function implement, respectively. ### Claim 4 (depends on 1) The work vehicle MRF joystick system of claim 1, wherein the joystick device comprises at least one resilient element biasing the joystick to return to a center position when the joystick is moved therefrom; and wherein the modified joystick stiffness mode comprises a joystick position hold mode in which the controller architecture commands the MRF joystick resistance mechanism to selectively increase the joystick stiffness in a manner preventing return of the joystick to the center position when the joystick is moved therefrom. ### Claim 5 (depends on 4) The work vehicle MRF joystick system of claim 4, wherein the controller architecture is further configured to place the work vehicle MRF joystick system in the modified joystick stiffness mode in response to operator input transitioning the work vehicle from a velocity-based joystick steering scheme to a position-based joystick steering scheme. ### Claim 6 (depends on 1) The work vehicle MRF joystick system of claim 1, wherein the work vehicle is operable in a multiple performance modes; and wherein the controller architecture is configured to selectively place the work vehicle MRF joystick system in the modified joystick stiffness mode based, at least in part, on operator input data placing the work vehicle in a selected one of the multiple performance modes. ### Claim 7 (depends on 1) The work vehicle MRF joystick system of claim 1, wherein the work vehicle is operable in a creep mode in which the joystick device can be utilized to control movement of the work vehicle in at least forward and rearward directions; and wherein the controller architecture is configured to selectively place the work vehicle MRF joystick system in the modified joystick stiffness mode when the work vehicle is placed in the creep mode. ### Claim 8 (depends on 7) The work vehicle MRF joystick system of claim 7, wherein, when the work vehicle MRF joystick system is placed in the modified joystick mode, the controller architecture: commands the MRF joystick resistance mechanism to generate one or more MRF detents at one or more predetermined joystick positions; and selectively causes continued creep of the work vehicle in a forward or rearward direction based upon joystick movement relative to the one or more MRF detents. ### Claim 9 (depends on 1) The work vehicle MRF joystick system of claim 1, wherein the controller architecture commands the MRF joystick resistance mechanism to generate one or more MRF detents at one or more predetermined joystick positions when the work vehicle MRF joystick system operates in a default joystick stiffness mode. ### Claim 10 (depends on 9) The work vehicle MRF joystick system of claim 9, wherein controller architecture is further configured to: command the MRF joystick resistance mechanism to generate the one or more MRF detents at a first force level when the work vehicle MRF joystick system operates in a default joystick stiffness mode; and command the MRF joystick resistance mechanism to generate the one or more MRF detents a second force level different than the first force level when the work vehicle MRF joystick system operates in a default joystick stiffness mode. ### Claim 11 (depends on 9) The work vehicle MRF joystick system of claim 9, wherein the controller architecture is configured to control the MRF joystick resistance mechanism to suppress generation of the one or more MRF detents when the work vehicle MRF joystick system operates in a default joystick stiffness mode. ### Claim 12 (depends on 1) The work vehicle MRF joystick system of claim 1, wherein the modified joystick stiffness mode comprises a calibration mode during which a calibration process is carried-out; and wherein the controller architecture is configured to command the MRF joystick resistance mechanism to generate an MRF detent at a calibration position providing a tactile cue for an operator to maintain the joystick in the calibration position until completion of the calibration process. ### Claim 13 (depends on 1) The work vehicle MRF joystick system of claim 1, further comprising a memory accessible to the controller architecture and storing an operator customization profile; wherein the modified joystick stiffness mode comprises an operator-customized stiffness mode; and wherein the controller architecture is further configured to: place the work vehicle MRF joystick system in the operator-customized stiffness mode in response to identification of an operator of the work vehicle associated with the operator customization profile; and when the work vehicle MRF joystick system is placed in the operator-customized stiffness mode, command the MRF joystick resistance mechanism to vary the joystick stiffness in accordance with the operator customization profile. ### Claim 14 (depends on 1) The work vehicle MRF joystick system of claim 1, wherein the work vehicle comprises an electrohydraulic (EH) actuation system operable in modified EH control mode, the modified EH control mode comprising a lift mode or a pressure boost mode; and wherein the controller architecture is configured to place the work vehicle MRF joystick system in the modified joystick stiffness mode in response to operator input activating the modified EH control mode. ### Claim 15 (depends on 1) The work vehicle MRF joystick system of claim 1, wherein the joystick is rotatable relative to the base housing about a first axis and a second axis substantially perpendicular to the first axis; wherein the controller architecture commands the MRF joystick resistance mechanism to permit joystick movement over a full range of motion (ROM) when operating in a default joystick stiffness mode; and wherein, when the work vehicle MRF joystick system is placed in the modified joystick stiffness mode, the controller architecture controls the MRF joystick resistance mechanism to selectively increase the joystick stiffness to confine joystick movement to a restricted ROM pattern comprising at least a first linear track. ### Claim 16 (depends on 15) The work vehicle MRF joystick system of claim 15, wherein the restricted ROM pattern comprises first and second linear tracks along which joystick movement is permitted, the first and second linear tracks substantially perpendicular and intersecting at a center position of the joystick. ### Claim 17 (depends on 1) The work vehicle MRF joystick system of claim 1, wherein a current speed of the work vehicle can be varied utilizing the joystick device; and wherein the controller architecture is further configured to: establish a target speed for the work vehicle based upon at least one performance parameter when the work vehicle MRF joystick system operates in the modified joystick stiffness mode; and command the MRF joystick resistance mechanism to vary the MRF joystick stiffness to provide tactile feedback through the joystick device indicating when the current speed of the work vehicle matches the target speed of the work vehicle. ### Claim 18 (depends on 1) The work vehicle MRF joystick system of claim 1, wherein the work vehicle comprises a grade control system and a blade positioned utilizing the joystick device; and wherein the controller architecture is configured to place the work vehicle MRF joystick system in the modified joystick stiffness mode when an operator controls the blade during a grading task carried-out utilizing the grade control system. ### Claim 19 (depends on 18) The work vehicle MRF joystick system of claim 18, wherein, when the work vehicle MRF joystick system operates in the modified joystick stiffness mode, the controller architecture commands the MRF joystick resistance mechanism to vary one or more of joystick stiffness characteristics relative to operation in a default joystick stiffness mode; and wherein the one or more joystick stiffness characteristics comprise: (i) changing a range of motion of the joystick, (ii) suppressing the generation of one or more MRF detents, and (iii) removing a float function of the blade. ### Claim 20 A work vehicle magnetorheological fluid (MRF) joystick system for usage 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; at least one resilient element within the base housing and exerting a bias force on the joystick urging return of the joystick to a center position when displaced therefrom; 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 a joystick stiffness resisting movement of the joystick 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 command the MRF joystick stiffness mechanism to: permit return of the joystick to the center position solely under the influence of the bias force when the work vehicle MRF joystick system operates in a first joystick stiffness mode; and prevent return of the joystick to the center position solely under the influence of the bias force when the work vehicle MRF joystick system operates in a second joystick stiffness mode.