# US 9,517,668 B2 · Hitch angle warning system and method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,517,668 B2 - Document ID: US9517668B2 - Status: Granted - Kind: B2 - Application number: 14/668,424 - Filed: 2015-03-25 - Published: 2016-01-28 - Granted: 2016-12-13 - Earliest claimed: 2014-07-28 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Erick Michael Lavoie - Web page: https://patentgrep.com/patent/US9517668B2 ## CPC - B60D 1/305: {Sway alarm means} - B60D 1/06: Ball-and-socket hitches - B60D 1/62: involving supply lines, electric circuits or the like - B62D 13/06: for backing a normally drawn trailer - B62D 15/027: {Parking aids, e.g. instruction means} - B62D 15/0285: {Parking performed automatically} - B60D 1/245: {for facilitating push back or parking of trailers} - B60D 1/30: for sway control {; Sway alarm means} - B60R 2300/307: virtually distinguishing relevant parts of a scene from the background of the scene - B60R 2300/607: from a bird's eye viewpoint - B60R 2300/80: characterised by the intended use of the viewing arrangement - B60W 2520/22: Articulation angle, e.g. between tractor and trailer - B60D: VEHICLE CONNECTIONS - 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) - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR - 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 ## Abstract A hitch angle warning system includes a camera-based hitch angle sensor that senses a hitch angle between a vehicle and a trailer. The hitch angle warning system also includes a controller that estimates an amount of time for the hitch angle to reach a threshold angle based on a rate of change of the hitch angle. The threshold angle may be set to a maximum hitch angle controllable by the vehicle based on a length of the trailer. The controller thereby generates a warning signal when the amount of time is less than a threshold time, which is configured to be greater or equal to than a response time of a driver of the vehicle to make a corrective action. The warning signal may be deactivated when the amount of time is greater than a second time that is greater than the threshold time. ## Claims ### Claim 1 A hitch angle warning system, comprising: a hitch angle sensor sensing a current hitch angle between a vehicle and a trailer; and a controller determining a future position of the trailer at a set time based on the current hitch angle and a speed of the vehicle and generating a warning signal when the future position exceeds a hitch angle threshold, wherein the future position is determined based on a length of the trailer, such that shorter length trailers will cause the warning signal to be generated before longer length trailers. ### Claim 2 (depends on 1) The hitch angle warning system of claim 1, further comprising: a display for showing a visible warning when the warning signal is generated. ### Claim 3 (depends on 1) The hitch angle warning system of claim 1, further comprising: a speaker for generating an audible warning when the warning signal is generated. ### Claim 4 (depends on 1) The hitch angle warning system of claim 1, wherein the future position is determined based on the speed of the vehicle. ### Claim 5 (depends on 1) The hitch angle warning system of claim 1, wherein the future position is determined based on the speed and a steering angle of the vehicle. ### Claim 6 (depends on 1) The hitch angle warning system of claim 1, wherein the future position includes a future hitch angle corresponding with a longitudinal centerline of the trailer in the future position. ### Claim 7 (depends on 1) The hitch angle warning system of claim 1, wherein the controller determines a maximum hitch angle controllable by the vehicle based on a length of the trailer, and wherein the hitch angle threshold is equal to the maximum hitch angle. ### Claim 8 (depends on 1) The hitch angle warning system of claim 1, wherein the controller generates a steering command for the vehicle to guide the trailer on a desired curvature based on a kinematic relationship between the vehicle and the trailer, wherein the desired curvature is defined with a steering input device. ### Claim 9 A hitch angle warning system, comprising: a hitch angle sensor sensing a hitch angle between a vehicle and a trailer; and a controller estimating an amount of time for the hitch angle to reach a threshold angle based on a rate of change of the hitch angle and generating a warning signal when the amount of time is less than a threshold time. ### Claim 10 (depends on 9) The hitch angle warning system of claim 9, wherein the rate of change of the hitch angle is determined based on repetitively sensing the hitch angle over time. ### Claim 11 (depends on 9) The hitch angle warning system of claim 9, wherein the threshold time is configured to be greater than a response time of a driver of the vehicle. ### Claim 12 (depends on 9) The hitch angle warning system of claim 9, wherein the warning signal is deactivated when the amount of time is greater than a second time that is greater than the threshold time. ### Claim 13 (depends on 9) The hitch angle warning system of claim 9, further comprising: a display for showing a visible warning when the warning signal is generated. ### Claim 14 (depends on 9) The hitch angle warning system of claim 9, further comprising: a speaker for generating an audible warning when the warning signal is generated. ### Claim 15 (depends on 9) The hitch angle warning system of claim 9, wherein the amount of time for the hitch angle to reach the threshold angle is determined based on at least one of a speed of the vehicle, a steering angle of the vehicle, and a length of the trailer. ### Claim 16 (depends on 9) The hitch angle warning system of claim 9, wherein the controller determines a maximum hitch angle controllable by the vehicle based on a length of the trailer, and wherein the threshold angle is substantially equal to the maximum hitch angle. ### Claim 17 A method for providing a hitch angle warning, comprising: reversing a vehicle with a trailer attached; sensing a hitch angle between the vehicle and the trailer; determining an amount of time for the hitch angle to reach a threshold angle; and generating a warning signal when the amount of time is less than a threshold time. ### Claim 18 (depends on 17) The method of claim 17, wherein the amount of time for the hitch angle to reach the threshold angle is determined based on a rate of change of the hitch angle. ### Claim 19 (depends on 18) The method of claim 18, further comprising: determining a maximum hitch angle controllable by the vehicle based on a length of the trailer, and wherein the threshold angle is substantially equal to the maximum hitch angle.