# US 2019/0168807 A1 · Controlling a steer-by-wire steering system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0168807 A1 - Document ID: US20190168807A1 - Status: Published application - Kind: A1 - Application number: 16/324,050 - Filed: 2017-08-08 - Published: 2019-06-06 - Earliest claimed: 2016-08-10 - Assignees: Thyssenkrupp Presta AG; thyssenkrupp AG - Applicants: Thyssenkrupp Presta AG; thyssenkrupp AG - Inventors: Kristof POLMANS - Web page: https://patentgrep.com/patent/US20190168807A1 ## CPC - B62D 6/008: {Control of feed-back to the steering input member, e.g. simulating road feel in steer-by-wire applications} - B62D 5/006: {power actuated} - B62D 5/0484: {for reaction to failures, e.g. limp home} - B62D 3/12: of rack-and-pinion type - B62D 15/021: {Determination of steering angle} - 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 vehicle steering system includes a steering actuator which acts on steered wheels, an actuation unit, a feedback actuator to which a user request for a steering angle can be applied using a steering input means, which outputs a feedback signal to the steering input means in response to the request and a driving state of the vehicle. A signal transmission transfers the request to the actuation unit. The actuation unit actuates the steering actuator to deflect the wheels. When a monitor detects a malfunction of the feedback actuator as a fault situation, the feedback signal and the signal transmission is modified or generated according to multiple options. ## Claims ### Claim at position 1 -9. (canceled) ### Claim 10 A steer-by-wire steering system for a motor vehicle, comprising: an electronically controllable steering actuator configured to act on steered wheels of the vehicle, an actuation unit, a feedback actuator configured such that a user request for a steering angle from a steering input means outputs a feedback signal to the steering input means as a reaction to the request and a driving state of the motor vehicle, a signal transmission configured to transfer the request to the actuation unit, wherein the actuation unit is configured to actuate the steering actuator to transform the request into a deflection of the steered wheels, and a feedback actuator monitor unit configured to detect a malfunction of the feedback actuator as a fault situation, wherein the system is configured to operate in the fault situation according to the following method: continuously reducing to zero the feedback signal to the steering input means within a first time period, and one or more of: reducing the signal transmission, and interrupting the signal transmission for a second time period, and only including the request which is transferred in the signal transmission as a reduced variable in the transformation for determining the change in the deflection of the wheels, and omitting the request which is transferred in the signal transmission, for the second time period, from the transformation for determining the change in the deflection of the wheels. ### Claim 11 (depends on 10) The system of claim 10, further comprising: determining a defined steering angle status based on a steering angle and a steering angle speed applied by the user during travel, transmitting the defined steering angle status to the actuation unit, and actuating the steering actuator based on the defined steering angle status. ### Claim 12 (depends on 10) The system of claim 10, further comprising: one or more of: measuring and storing a vehicle velocity, and measuring and storing the steered angle of the steered wheels, and measuring and storing a position of the steering actuator, and measuring or estimating a force of the steering actuator, wherein the force of the steering actuator is stored, wherein the stored values are stored for a third time period, and actuating the steering actuator on the basis of one or more of the stored vehicle velocity, the stored steered angle, the stored position of the steering actuator, and the stored or estimated force of the steering actuator. ### Claim 13 (depends on 11) The system of claim 11, including: determining, when in the fault situation, one or more of the feedback signal, the user request on the basis of the steering angle status which is determined before the fault situation, the measured vehicle velocity, the measured steered angle of the measured position of the steering actuator, and the measured or estimated force of the steering actuator. ### Claim 14 (depends on 10) The system of claim 10, wherein the second time period is shorter than the first time period. ### Claim 15 (depends on 10) The system of claim 10, including actuating, by means of the actuation unit, the feedback actuator after the expiry of the first time period. ### Claim 16 (depends on 10) The system of claim 10, wherein the driving state of the motor vehicle corresponds to cornering. ### Claim 17 A steer-by-wire steering system for a motor vehicle, comprising: an electronically controllable steering actuator configured to act on steered wheels of the motor vehicle, an actuation unit, a feedback actuator configured such that a user request for a steering angle can be applied by a user using a steering input means, and which outputs a feedback signal to the steering input means as a reaction to the request and a driving state of the motor vehicle, a signal transmission device configured to transfer the request to the actuation unit, wherein the actuation unit is configured to actuate the steering actuator in order to transform the request into a deflection of the steered wheels, wherein a feedback actuator monitor unit configured to monitor the feedback actuator and detect a malfunction of the feedback actuator as a fault situation, wherein the feedback actuator monitor unit is configured to reduce, in the fault situation, the feedback signal to the steering input means continuously to zero within a first time period, and one or more of: reduce the signal transmission between the steering input means and the steering actuator, and interrupt the signal transmission for a second time period, and transmit the driver's request, transferred in the signal transmission, only as a reduced variable, and transmit the driver's request, transferred in the signal transmission, into the transformation for determining the change in the deflection of the wheels in the actuation unit. ### Claim 18 (depends on 17) The steer-by-wire steering system of claim 17, wherein the steering actuator acts on the steered wheels with a rack-and-pinion steering gear.