# US 12,179,850 B2 · Steer-by-wire steering system for a two-track vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,179,850 B2 - Document ID: US12179850B2 - Status: Granted - Kind: B2 - Application number: 17/485,844 - Filed: 2021-09-27 - Published: 2022-04-21 - Granted: 2024-12-31 - Earliest claimed: 2020-10-21 - Assignees: Audi AG - Applicants: Audi AG - Inventors: Arne Minninger - Web page: https://patentgrep.com/patent/US12179850B2 ## CPC - B62D 5/006: {power actuated} - B62D 5/001: {Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup} - B62D 5/0481: {monitoring the steering system, e.g. failures} - B62D 5/0484: {for reaction to failures, e.g. limp home} - B62D 6/00: Arrangements for automatically controlling steering depending on driving conditions sensed and responded to, e.g. control circuits (means for initiating a change in direction B62D1/00; steering valves B62D5/06; combined with means for inclining the vehicle body or wheels on bends B62D9/00) - B62D 6/008: {Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications} - B62D 15/029: {Steering assistants using warnings or proposing actions to the driver without influencing the steering system} - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) ## Abstract A steer-by-wire steering system for a vehicle, having a steering handle, a steering gear actuator mechanically decoupled from the steering handle, a steering sensor which detects a rotational position and/or a rotational movement of the steering handle as a steering command, an electronic control unit which, as a function of the detected steering command, activates the steering gear actuator to set a vehicle wheel steering angle (α), and a hand actuator activatable by the control unit, which generates different types of haptic feedback (R1, R2, R3) for the driver on the steering handle, namely a haptic steering feedback (R1) in which a steering counter torque is applied to the steering handle, a roadway feedback (R2), which correlates with a roadway-side disturbance excitation acting on the vehicle, and a warning feedback (R3), which informs the driver of a fault in the steer-by-wire steering system. ## Claims ### Claim 1 A steer-by-wire steering system for a vehicle, comprising: a steering handle, having a steering gear actuator mechanically decoupled from the steering handle, a steering sensor which detects a rotational position and/or a rotational movement of the steering handle as a steering command, an electronic control unit which, as a function of the detected steering command, activates the steering gear actuator to set a vehicle wheel steering angle (α), and a hand actuator activatable by the control unit, which generates haptic feedback (R1, R2, R3) for a driver on the steering handle, which is a haptic steering feedback (R1), in which a steering counter torque is applied to the steering handle, in a steering process, a roadway feedback (R2), which correlates with a roadway-side disturbance excitation acting on the vehicle, and a warning feedback (R3), which informs the driver of a fault in the steer-by-wire steering system, wherein the control unit is associated with an evaluation unit, by which the roadway feedback (R2) can at least be weakened or deactivated in the event of the steering system fault so that a perceptibility of the warning feedback (R3) is increased for the driver. ### Claim 2 (depends on 1) The steer-by-wire steering system according to claim 1, wherein a steering converter module is associated with the control unit which, during a steering process, generates a steering counter torque signal (SL), by which the hand actuator is activatable to generate the steering feedback (R1) on the steering handle. ### Claim 3 (depends on 2) The steer-by-wire steering system according to claim 2, wherein a roadway converter module is associated with the control unit which generates a roadway signal (SF) based on the roadway-side disturbance excitation, by which the hand actuator is activatable to generate the roadway feedback (R2) on the steering handle. ### Claim 4 (depends on 2) The steer-by-wire steering system according to claim 2, wherein a diagnostic module is associated with the control unit which, in the event of the steering system fault, generates a warning signal (SW), by which the hand actuator is activatable to generate the warning feedback (R3) on the steering handle and/or by which an output unit is activatable to, in addition to the warning feedback (R3), generate an acoustic and/or visual warning message on the output unit. ### Claim 5 (depends on 2) The steer-by-wire steering system according claim 2, wherein the haptic feedback (R1, R2, R3) which can be provided on the steering handle (5) can be partially superimposed on one another. ### Claim 6 (depends on 2) The steer-by-wire steering system according to claim 2, wherein the haptic warning feedback (R3) is a steering handle vibration. ### Claim 7 (depends on 1) The steer-by-wire steering system according to claim 1, wherein a roadway converter module is associated with the control unit which generates a roadway signal (SF) based on the roadway-side disturbance excitation, by which the hand actuator is activatable to generate the roadway feedback (R2) on the steering handle. ### Claim 8 (depends on 7) The steer-by-wire steering system according to claim 7, wherein a diagnostic module is associated with the control unit which, in the event of a steering system fault, generates a warning signal (SW), by which the hand actuator is activatable to generate the warning feedback (R3) on the steering handle and/or by which an output unit is activatable to, in particular in addition to the warning feedback (R3), generate an acoustic and/or visual warning message on the output unit. ### Claim 9 (depends on 7) The steer-by-wire steering system according claim 7, wherein the haptic feedback (R1, R2, R3) which can be provided on the steering handle can be partially superimposed on one another. ### Claim 10 (depends on 7) The steer-by-wire steering system according to claim 7, wherein the haptic warning feedback (R3) is a steering handle vibration. ### Claim 11 (depends on 1) The steer-by-wire steering system according to claim 1, wherein a diagnostic module is associated with the control unit which, in the event of the steering system fault, generates a warning signal (SW), by which the hand actuator is activatable to generate the warning feedback (R3) on the steering handle and/or by which an output unit is activatable to, in addition to the warning feedback (R3), generate an acoustic and/or visual warning message on the output unit. ### Claim 12 (depends on 11) The steer-by-wire steering system according to claim 11, wherein by the diagnostic module for recognizing the steering system fault, at least one steering system parameter, a steering system operating voltage level (UB), is detectable and comparable to a predefined steering system target parameter, a steering system target operating voltage level (USOLL), and that the warning signal (SW) can be generated by the diagnostic module in particular if the steering system target parameter is exceeded or not reached. ### Claim 13 (depends on 12) The steer-by-wire steering system according claim 12, wherein the haptic feedback (R1, R2, R3) which can be provided on the steering handle can be partially superimposed on one another. ### Claim 14 (depends on 11) The steer-by-wire steering system according claim 11, wherein the haptic feedback (R1, R2, R3) which can be provided on the steering handle can be partially superimposed on one another. ### Claim 15 (depends on 11) The steer-by-wire steering system according to claim 11, wherein the haptic warning feedback (R3) is a steering handle vibration. ### Claim 16 (depends on 1) The steer-by-wire steering system according claim 1, wherein the haptic feedback (R1, R2, R3) which can be provided on the steering handle can be partially superimposed on one another. ### Claim 17 (depends on 1) The steer-by-wire steering system according to claim 1, wherein the haptic warning feedback (R3) is a steering handle vibration. ### Claim 18 (depends on 1) The steer-by-wire steering system according to claim 1, wherein a signal processing unit activatable by the evaluation unit is interconnected in a signal path from the steering converter module to the hand actuator, and that in the event of the steering system fault, the signal processing unit is activatable by the evaluation unit so that signal transmission of a roadway signal (SF) to the hand actuator is blocked or a modified roadway signal (SF′) can be generated in the signal processing unit, by which a weakened roadway feedback (R2) is applicable to the steering handle. ### Claim 19 (depends on 18) The steer-by-wire steering system according to claim 18, wherein the weakened roadway feedback (R2) has a reduced amplitude and/or a reduced frequency in comparison to the roadway feedback (R2) in normal steering system operation. ### Claim 20 (depends on 1) A method for operating a steer-by-wire steering system according to claim 1.