Trailer path curvature control for trailer backup assist

• US 8,909,426 B2
• Filed: 12/23/2011
• Issued: 12/09/2014
• Est. Priority Date: 04/19/2011
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company), Board of Regents of the University of Michigan (University of Michigan)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company), Board of Regents of the University of Michigan (University of Michigan)
• Inventors: Rhode, Douglas Scott, Smit, David Dean, Lavoie, Erick Michael, Frey, Martin Fitzpatrick, Pilutti, Thomas Edward, Shim, Taehyun, Rupp, Matt Y., Trombley, Roger Arnold
• Primary Examiner(s): MANCHO, RONNIE M
• Application Number:
  US13/336,060
• Publication Number:
  US 20120271515A1
• Time in Patent Office: 1,082 Days
• Field of Search: 701/41, 701/36, 280/426, 280/448
• US Class Current: 701/41
• CPC Class Codes: B60W 2300/14 Tractor-trailers, i.e. combinations of a towing vehicle and one or more towed vehicles, e.g. caravans; Road trains
• CPC Class Codes: B60W 2520/22 Articulation angle, e.g. between tractor and trailer
• CPC Class Codes: B60W 2710/207 Steering angle of wheels
• CPC Class Codes: B60W 30/06 Automatic manoeuvring for parking
• CPC Class Codes: B60W 30/18036 Reversing
• CPC Class Codes: B60Y 2200/147 Trailers, e.g. full trailers or caravans
• CPC Class Codes: B62D 1/22 Alternative steering-control elements, e.g. for teaching purposes
• CPC Class Codes: B62D 13/06 for backing a normally drawn trailer
• CPC Class Codes: B62D 15/027 Parking aids, e.g. instruction means

Abstract

A vehicle has a trailer backup steering input apparatus, a trailer backup assist control module coupled to the a trailer backup steering input apparatus, and an electric power assist steering system coupled to the trailer backup assist control module and. The trailer backup steering input apparatus is configured for outputting a trailer path curvature signal approximating a desired curvature for a path of travel of a trailer towably coupled to the vehicle. The trailer backup assist control module is configured for determining vehicle steering information as a function of the trailer path curvature signa. The electric power assist steering system is configured for controlling steering of steered wheels of the vehicle as a function of the vehicle steering information.

Claims

1. A method of controlling a path of travel of a trailer towably coupled to a vehicle during backing of the trailer by the vehicle, comprising:

receiving trailer path curvature information characterizing a desired curvature for the path of travel of the trailer, the desired curvature is relative to a zero curvature position that is defined by backward movement of the trailer along a substantially straight path defined by a centerline longitudinal axis of the trailer;

determining vehicle steering information through assessment of kinematical information of a system defined by the vehicle and the trailer, assessment of the kinematical information is performed as a function of the trailer path curvature information; and

generating a steering command for a steering system of the vehicle as a function of the vehicle steering information.

2. The method of claim 1 wherein determining the vehicle steering information includes:

determining a jackknife angle for the system; and

determining a steering angle for steered wheels of the vehicle required for limiting a potential for the system achieving the jackknife angle.

3. The method of claim 1 wherein the kinematical information includes:

hitch angle defined between the vehicle and the trailer;

a wheel base dimension of the vehicle;

a rear axle-to-hitch rotation point for the vehicle; and

an axle-to-hitch rotation point for the trailer.

4. The method of claim 1 wherein receiving the trailer path curvature information includes receiving the trailer path curvature information from a trailer backup steering input apparatus that is mechanically detached from steered wheels of the vehicle.

5. The method of claim 4 wherein an output:

signal of the trailer backup steering input apparatus is a function of an input signal approximating the desired curvature for the path of travel of the trailer.

6. The method of claim 1 generating the steering command includes generating a steering system command signal for causing the steering system to alter a steering angle of steered wheels thereof such that a corresponding maneuver of the vehicle results in the trailer achieving a path of travel having a curvature that approximates the desired curvature.

7. The method of claim 6 wherein:

determining the vehicle steering information includes determining a jackknife angle for the system and determining a steering angle for the steered wheels of the vehicle required for limiting a potential for the system achieving the jackknife angle; and

the steering system command signal is a function of the steering angle.

8. The method of claim 6 wherein:

receiving the trailer path curvature information includes receiving the trailer path curvature information from a trailer backup steering input apparatus that is mechanically detached from steered wheels of the vehicle; and

an output signal of the trailer backup steering input apparatus is a function of an input signal approximating the desired curvature for a path of travel of the trailer.

9. The method of claim 8 wherein:

determining the vehicle steering information includes determining a jackknife angle for the system and determining a steering angle for the steered wheels of the vehicle required for precluding the system from achieving the jackknife angle; and

the steering system command signal is a function of the steering angle.

10. An electronic control system having a set of instructions tangibly embodied on a non-transitory processor-readable medium thereof, the set of instructions are accessible from the non-transitory processor-readable medium by at least one data processing device of the electronic controller system for being interpreted thereby, and the set of instructions is configured for causing the at least one data processing device to carry out operations for:

receiving trailer path curvature information characterizing a desired curvature for a path of travel of a trailer during backing of the trailer by a vehicle towably coupled thereto, the desired curvature is relative to a zero curvature position defined by backward movement of the trailer in a substantially straight line defined by a centerline longitudinal axis of the trailer;

determining vehicle steering information through assessment of kinematical information of a system defined by the vehicle and the trailer, assessment of the kinematical information is performed as a function of the trailer path curvature information; and

generating a steering command for a steering system of the vehicle as a function of the vehicle steering information.

11. The electronic control system of claim 10 wherein determining the vehicle steering information includes:

determining a jackknife angle for the system; and

determining a steering angle for steered wheels of the vehicle required for limiting a potential for the system achieving the jackknife angle.

12. The electronic control system of claim 10 wherein the kinematical information includes:

hitch angle defined between the vehicle and the trailer;

a wheel base dimension of the vehicle;

a rear axle-to-hitch rotation point for the vehicle; and

an axle-to-hitch rotation point for the trailer.

13. The electronic control system of claim 10 wherein:

the electronic control system comprises a trailer backup steering input apparatus;

receiving the trailer path curvature information includes receiving the trailer path curvature information from the trailer backup steering input apparatus that is mechanically detached from steered wheels of the vehicle; and

an output signal of the trailer backup steering input apparatus is a function of an input signal approximating the desired curvature for the path of travel of the trailer.

14. The electronic control system of claim 10 generating the steering command includes generating a steering system command signal for causing the steering system to alter a steering angle of steered wheels thereof such that a corresponding maneuver of the vehicle results in the trailer achieving a path of travel having a curvature that approximates the desired curvature.

15. The electronic control system of claim 14 wherein:

determining the vehicle steering information includes determining a jackknife angle for the system and determining a steering angle for the steered wheels of the vehicle required for limiting a potential for the system achieving the jackknife angle; and

the steering system command signal is a function of the steering angle.

16. The electronic control system of claim 14 wherein:

the electronic control system comprises a trailer backup steering input apparatus;

receiving the trailer path curvature information includes receiving the trailer path curvature information from the trailer backup steering input apparatus that is mechanically detached from steered wheels of the vehicle; and

an output signal of the trailer backup steering input apparatus is a function of an input signal.

17. A trailer backup assist system for a vehicle, comprising:

a trailer backup steering input apparatus for outputting a trailer path curvature signal approximating a desired curvature for a path of travel of a trailer towably coupled to the vehicle, the desired curvature is relative to a zero curvature position defined by backward movement of the trailer in a straight path defined by a centerline longitudinal axis of the trailer;

a trailer backup assist control module coupled to the a trailer backup steering input apparatus and configured for determining vehicle steering information as a function of the trailer path curvature signal; and

an electric power assist steering system coupled to the trailer backup assist control module and configured for controlling steering of steered wheels of the vehicle as a function of the vehicle steering information.

18. The system of claim 17 wherein determining the vehicle steering information includes assessing kinematical information of a system defined by the vehicle and the trailer.

21. The system of claim 17 wherein the trailer backup steering input apparatus is mechanically detached from steered wheels of the vehicle.

22. The system of claim 17 wherein determining the vehicle steering information includes generating a steering system command signal for causing the electric power assist steering system to alter a steering angle of steered wheels thereof such that a corresponding maneuver of the vehicle results in the trailer achieving a path of travel having a curvature that approximates the desired curvature.

23. The system of claim 22 wherein:

determining the vehicle steering information includes determining a jackknife angle for the system and determining a steering angle for the steered wheels of the vehicle required for limiting a potential for the system achieving the jackknife angle; and

the steering system command signal is a function of the steering angle.

24. The system of claim 23 wherein determining the vehicle steering information includes assessing kinematical information of a system defined by the vehicle and the trailer.

19. The system of 18 wherein determining the vehicle steering information includes:

determining a jackknife angle for the system; and

determining a steering angle for the steered wheels of the vehicle required for limiting a potential for the system achieving the jackknife angle.

20. The system of claim 19 wherein the kinematical information utilized in determining the jackknife angle includes:

a maximum steered angle for steered wheels of the vehicle;

a wheel base dimension of the vehicle;

a rear axle-to-hitch rotation point for the vehicle; and

an axle-to-hitch rotation point for the trailer.

25. A method of controlling a path of travel of a trailer towably coupled to a vehicle during backing of the trailer by the vehicle, comprising:

receiving trailer angle information from a trailer angle detection apparatus of a vehicle having a trailer attached thereto, wherein the trailer angle information is generated as a function of an angular displacement between the vehicle and the trailer;

receiving trailer path curvature information characterizing a desired curvature for a path of travel of the trailer from a trailer backup steering input apparatus of the vehicle, the trailer backup steering input apparatus includes a rotational control input device positionable at a zero curvature commanding position and at positions within opposing rotational ranges of motion relative to the zero curvature commanding position and the trailer steering information is derived from at least one of an amount of rotation of the rotational control input device with respect to the zero curvature commanding position, a rate movement of the rotational control input device, and a direction of movement of the rotational control input device with respect to the zero curvature commanding position;

determining vehicle steering information through assessment of kinematical information of a system defined by the vehicle and the trailer, assessment of kinematical information is performed as a function of the trailer path curvature information;

generating a steering command for a steering system of the vehicle as a function of the vehicle steering information; and

controlling a power steering system of the vehicle using vehicle steering information as the trailer is being backed by the vehicle, the vehicle steering information is generated as a function of the trailer angle information and the trailer path curvature information.

26. The method of claim 25 wherein the vehicle steering information causes the trailer to travel along a commanded curvature of a path of travel when the rotational control input device is in a position other than the zero curvature commanding position.

27. The method of claim 26 wherein:

a first one of the opposing rotational ranges of motion is substantially equal to a second one of the opposing rotational ranges of motion; and

a chance in curvature of the path of travel of the trailer varies as a function of the amount of rotation of the rotational control input device.

28. The method of claim 27 wherein controlling the power steering system includes:

causing the power steering system to steer the vehicle such that a the curvature of the path of travel of the trailer is altered as a function of an amount and direction of rotation of the rotational input device relative to the zero curvature commanding position while the trailer is being backed up by the vehicle; and

causing the power steering system to steer the vehicle such that the trailer is backed along a substantially straight line as defined by a centerline longitudinal axis of the trailer at a point in time when the rotational control input device is returned to the zero curvature commanding position from a position other than the zero curvature commanding position.

29. The method of claim 25 wherein determining the vehicle steering information includes:

determining a jackknife angle for the system; and

determining a steering angle for steered wheels of the vehicle required for limiting a potential for the system achieving the jackknife angle.

30. The method of claim 25 wherein the kinematical information includes:

hitch angle defined between the vehicle and the trailer;

a wheel base dimension of the vehicle;

a rear axle-to-hitch rotation point for the vehicle; and

an axle-to-hitch rotation point for the trailer.

31. The method of claim 25 generating the steering command includes generating a steering system command signal for causing the steering system to alter a steering angle of steered wheels thereof such that a corresponding maneuver of the vehicle results in the trailer achieving a path of travel having a curvature that approximates the desired curvature.

32. The method of claim 30 wherein:

determining the vehicle steering information includes determining a jackknife angle for the system and determining a steering angle for the steered wheels of the vehicle required for limiting a potential for the system achieving the jackknife angle; and

the steering system command signal is a function of the steering angle.

33. A trailer backup steering system for a vehicle, comprising:

a trailer angle detection apparatus configured for outputting a signal generated as a function of an angle between the vehicle and a trailer attached to the vehicle;

a trailer backup steering input apparatus for outputting a trailer path curvature signal approximating a desired curvature for a path of travel of a trailer towably coupled to the vehicle, the desired curvature is relative to a zero curvature position defined by backward movement of the trailer along a straight path defined by a centerline longitudinal axis of the trailer, the trailer backup steering input apparatus including a knob and a knob movement sensing device coupled to the knob for sensing movement of the knob, the knob is biased to an at-rest position between opposing rotational ranges of motion, the at-rest position corresponds to the zero curvature position, the knob movement sensing device outputs a signal generated as a function of at least one of an amount of rotation of the knob with respect to the at-rest position, a rate movement of the knob, and a direction of movement of the knob with respect to the at-rest position;

a trailer backup assist control module coupled to the a trailer backup steering input apparatus and configured for determining vehicle steering information as a function of the trailer path curvature signal; and

a power-steering assist system coupled to a trailer angle detection apparatus, the trailer backup steering input apparatus, and the trailer backup assist control module, the power-steering assist system includes a control module structure configured for generating power steering system control information as a function of the trailer angle detection apparatus signal and the backup steering input apparatus signal and controlling steering of steered wheel of the vehicle as a function of the vehicle steering information.

34. The system of claim 33 wherein determining the vehicle steering information includes:

determining a jackknife angle for the system; and

determining a steering angle for the steered wheels of the vehicle required for limiting a potential for the system achieving the jackknife angle.

35. The system of claim 34 wherein he kinematical information utilized in determining the jackknife angle includes:

a maximum steered angle for steered wheels of the vehicle;

a wheel base dimension of the vehicle;

a rear axle-to-hitch rotation point for the vehicle; and

an axle-to-hitch rotation point for the trailer.

36. The system of claim 33 wherein the trailer backup steering input apparatus further includes at least one of:

a visual indicator being selectively activated to provide notification of an unacceptable trailer backup condition;

an audible indicator being selectively activated to provide notification of the unacceptable trailer backup condition; and

a tactile indicator being selectively activated to provide notification of the unacceptable trailer backup condition.

37. The system of claim 33 wherein the knob movement sensing device signal outputted when the knob is in a position other than the at-rest position corresponds to a curvature of a path of travel of the trailer over which the trailer travels while being backed by the vehicle.

38. The system of claim 37 wherein:

a first one of the opposing rotational ranges of motion is substantially equal to a second one of the opposing rotational ranges of motion; and

a change in curvature of the path of travel of the trailer varies as a function of the amount of rotation of the knob.

39. The system of claim 38 wherein a force biasing the knob toward the at-rest position increases as a function of the amount of rotation of the knob with respect to the at-rest position.

40. The system of claim 33 wherein a force biasing the knob toward the at-rest position increases as a function of the amount of rotation of the knob with respect to the at-rest position.