Hitch angle warning system and method

• US 9,517,668 B2
• Filed: 03/25/2015
• Issued: 12/13/2016
• Est. Priority Date: 07/28/2014
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lavoie, Erick Michael
• Primary Examiner(s): Edwards, Jerrah
• Assistant Examiner(s): SMITH-STEWART, DEMETRA R
• Application Number:
  US14/668,424
• Publication Number:
  US 20160023526A1
• Time in Patent Office: 629 Days
• US Class Current: 1/1
• CPC Class Codes: B60D 1/06 Ball-and-socket hitches , e.g. constructional details, auxiliary devices, their arrangement on the vehicle
• CPC Class Codes: B60D 1/245 for facilitating push back or parking of trailers
• CPC Class Codes: B60D 1/30 for sway control , e.g. stabilising or anti-fishtail devices; Sway alarm means
• CPC Class Codes: B60D 1/305 Sway alarm means
• CPC Class Codes: B60D 1/62 involving supply lines, electric circuits, or the like
• CPC Class Codes: B60R 2300/307 virtually distinguishing relevant parts of a scene from the background of the scene
• CPC Class Codes: B60R 2300/607 from a bird's eye viewpoint
• CPC Class Codes: B60R 2300/80 characterised by the intended use of the viewing arrangement
• CPC Class Codes: B60W 2520/22 Articulation angle, e.g. between tractor and trailer
• CPC Class Codes: B62D 13/06 for backing a normally drawn trailer
• CPC Class Codes: B62D 15/027 Parking aids, e.g. instruction means
• CPC Class Codes: B62D 15/0285 Parking performed automatically

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

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.

2. The hitch angle warning system of claim 1, further comprising:

a display for showing a visible warning when the warning signal is generated.

3. The hitch angle warning system of claim 1, further comprising:

a speaker for generating an audible warning when the warning signal is generated.

4. The hitch angle warning system of claim 1, wherein the future position is determined based on the speed of the vehicle.

5. 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.

6. 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.

7. 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.

8. 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.

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.

10. 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.

11. 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.

12. 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.

13. The hitch angle warning system of claim 9, further comprising:

a display for showing a visible warning when the warning signal is generated.

14. The hitch angle warning system of claim 9, further comprising:

a speaker for generating an audible warning when the warning signal is generated.

15. 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.

16. 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.

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.

18. 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.

19. 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.