# US 9,517,794 B2 · Offset compensation for trailer backup assist steering input device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,517,794 B2 - Document ID: US9517794B2 - Status: Granted - Kind: B2 - Application number: 14/447,184 - Filed: 2014-07-30 - Published: 2014-11-20 - Granted: 2016-12-13 - Earliest claimed: 2011-04-19 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Erick Michael Lavoie - Web page: https://patentgrep.com/patent/US9517794B2 ## CPC - B62D 13/06: for backing a normally drawn trailer - B60W 10/04: including control of propulsion units - B60W 10/18: including control of braking systems - B60W 30/18036: {Reversing} - B62D 15/027: {Parking aids, e.g. instruction means} - B60K 35/10: Input arrangements, i.e. from user to vehicle, associated with vehicle functions or specially adapted therefor - B60K 2360/126: Rotatable input devices for instruments - B60W 10/20: including control of steering systems - B60W 2300/14: Tractor-trailers, i.e. combinations of a towing vehicle and one or more towed vehicles, e.g. caravans; Road trains - B60W 2520/10: Longitudinal speed - B60W 2520/22: Articulation angle, e.g. between tractor and trailer - B60W 2540/18: Steering angle - B60W 2540/215: Selection or confirmation of options - B60W 2720/22: Articulation angle, e.g. between tractor and trailer - 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) - B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT - B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES ## Abstract A trailer backup assist system for a vehicle reversing a trailer, according to one embodiment, includes a sensor that senses a hitch angle between the vehicle and the trailer. The trailer backup assist system may also include a steering input device, such as a rotatable knob, that is movable between a plurality of positions that each provide a desired curvature of the trailer. In addition, the trailer backup assist system may include a controller that determines an offset of the desired curvature when the knob is stationary in a central position. The control then generates a steering command for the vehicle to guide the trailer on the desired curvature, taking into consideration the offset. ## Claims ### Claim 1 A trailer backup assist system for a vehicle reversing a trailer, comprising: a knob disposed in the vehicle and having a position indicator, the knob rotatable from a biased position to a number of positions, each position of the knob outputting a signal aligned with the position indicator and indicative of a desired curvature for a backup path of the vehicle and the trailer; and a controller configured to: determine a signal offset when the knob is returned to the biased position and the signal outputted from the knob is out of alignment with the position indicator; apply the signal offset to the outputted signal such that the outputted signal is realigned with the position indicator; and generate a steering command for the vehicle to guide the trailer on the desired curvature according to the outputted signal to which the signal offset was applied. ### Claim 2 (depends on 1) The trailer backup assist system of claim 1, wherein the knob is spring biased to the biased position and rotatable therefrom in a clockwise direction or a counterclockwise direction. ### Claim 3 (depends on 1) The trailer backup assist system of claim 1, wherein the knob is spring biased to the biased position and wherein when the signal outputted from the biased position is in alignment with the position indicator, the signal provides a zero curvature value for backing the vehicle and the trailer along a straight trajectory. ### Claim 4 (depends on 1) The trailer backup assist system of claim 1, further comprising: a torque sensor coupled with the knob, wherein the controller determines the knob is in the biased position when the torque sensor fails to sense external torque on the knob and the controller determines that a rate of rotation of the knob is within a threshold range including. ### Claim 5 (depends on 4) The trailer backup assist system of claim 4, wherein the threshold range is between and inclusive of positive 0.5 degrees per second and negative 0.5 degrees per second. ### Claim 6 A trailer backup assist system for a vehicle reversing a trailer, comprising: a steering input device disposed in the vehicle and having a position indicator, the steering input device movable from a biased position to a number of positions, each position of the steering input device outputting a signal aligned with the position indicator and indicative of a desired curvature for a backup path of the vehicle and the trailer; and a controller configured to: determine a signal offset when the steering input device is returned to the biased position and the signal outputted from the knob is out of alignment with the position indicator; apply the signal offset to the signal such that the signal is realigned with the position indicator; and generate a steering command for the vehicle to guide the trailer on the desired curvature according to the signal to which the signal offset was applied. ### Claim 7 (depends on 6) The trailer backup assist system of claim 6, wherein the steering input device includes a knob that is spring biased to the biased position and is rotatable therefrom in a clockwise direction or a counterclockwise direction. ### Claim 8 (depends on 6) The trailer backup assist system of claim 6, wherein the steering input device includes a knob that is spring biased to the biased position and wherein when the signal outputted from the biased position is in alignment with the position indicator, the signal provides a zero curvature value for backing the vehicle and the trailer along a straight trajectory. ### Claim 9 (depends on 6) The trailer backup assist system of claim 6, further comprising: a torque sensor coupled with the knob, wherein the controller determines the knob is in the biased position when the torque sensor fails to sense external torque on the knob and the controller determines that a rate of rotation of the knob is within a threshold range including zero. ### Claim 10 (depends on 9) The trailer backup assist system of claim 9, wherein the threshold range is between and inclusive of positive 0.5 degrees per second and negative 0.5 degrees per second. ### Claim 11 A method for reversing a vehicle attached to a trailer, comprising: providing a knob inside the vehicle and having a position indicator, the knob rotatable from a biased position to a number of positions, each position of the knob outputting a signal aligned with the position indicator and indicative of a desired curvature for a backup path of the vehicle and the trailer; and providing a controller configured to: determine a signal offset when the knob is returned to the biased position and the signal outputted from the knob is out of alignment with the position indicator; apply the signal offset to the outputted signal such that the outputted signal is realigned with the position indicator; and generate a steering command for the vehicle to guide the trailer on the desired curvature according to the outputted signal to which the signal offset was applied. ### Claim 12 (depends on 11) The method of claim 11, wherein the knob is spring biased to the biased position and rotatable therefrom in a clockwise direction or a counterclockwise direction. ### Claim 13 (depends on 11) The method of claim 11, wherein the knob is spring biased to the biased position, and wherein when the signal outputted from the biased position is in alignment with the position indicator, the signal provides a zero curvature value for backing the vehicle and the trailer along a straight trajectory. ### Claim 14 (depends on 11) The method of claim 11, further comprising: a torque sensor coupled with the knob, wherein the controller determines the knob is in the biased position when the torque sensor fails to sense external torque on the knob and the controller determines that a rate of rotation of the knob is within a threshold range including zero. ### Claim 15 (depends on 14) The method of claim 14, wherein the rate, of rotation is within a threshold range is between and inclusive of positive 0.5 degrees per second and negative 0.5 degrees per second.