System and method for providing a corrected lane following path through a curve for trailering vehicles

• US 9,849,878 B2
• Filed: 02/26/2016
• Issued: 12/26/2017
• Est. Priority Date: 02/26/2016
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Lee, Jin-Woo, Litkouhi, Bakhtiar B.
• Primary Examiner(s): GOLDMAN, RICHARD A
• Application Number:
  US15/054,705
• Publication Number:
  US 20170247032A1
• Time in Patent Office: 669 Days
• Field of Search: 701 23, 701 1, 701 41, 701 25, 701 314, 701 45, 701 48, 701 71, 701 81
• CPC Class Codes: B60W 2050/143 Alarm means
• 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 2540/18 Steering angle
• CPC Class Codes: B60W 2552/30 Road curve radius
• CPC Class Codes: B60W 30/12 Lane keeping
• CPC Class Codes: B60W 30/18145 Cornering
• CPC Class Codes: B60W 30/18163 Lane change; Overtaking manoeuvres
• CPC Class Codes: B60W 40/072 Curvature of the road
• CPC Class Codes: B62D 13/00 Steering specially adapted for trailers combined traction and steering hitches B60D
• CPC Class Codes: B62D 15/021 Determination of steering angle
• CPC Class Codes: B62D 15/025 Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation B62D1/28 takes precedence

Abstract

A method for providing vehicle steering control through a curve in an autonomously driven or semi-autonomously driven vehicle that is towing a trailer. The method determines that the trailer will cross out of the travel lane based on the curvature of the curve and the turn radius of the trailer. The method calculates a start turn radius of the vehicle for a start location of the curve, an end turn radius of the vehicle for an end location of the curve, and a turn end point proximate the end location or a turn start point proximate the start location. The method provides initial and boundary conditions for determining a desired path of the vehicle through the curve that prevents the trailer from crossing out of the lane and determines the desired path based on the initial and boundary conditions by solving a polynomial equation.

Claims

1. A method for providing vehicle steering control in an autonomously driven or semi-autonomously driven vehicle that is towing a trailer so as to prevent the trailer from crossing out of a travel lane in a curve that the vehicle is traveling along, said method comprising:

using a processor programmed for;

determining a radius of curvature of the curve, a width of the travel lane, and a length of the trailer;

determining when the vehicle has entered the curve;

determining a current steering angle of the vehicle;

determining a current turn radius of the vehicle for traveling through the curve using the current steering angle;

determining a turn radius of the trailer using the current turn radius of the vehicle and other parameters;

determining that the trailer will cross out of the travel lane based on the radius of curvature of the curve and the turn radius of the trailer;

calculating a start turn radius of the vehicle for a start location of the curve;

calculating an end turn radius of the vehicle for an end location of the curve;

determining a turning end point proximate the end location;

determining a turning start point proximate the start location; and

determining a desired path of the vehicle through the curve that prevents the trailer from crossing out of the lane that includes solving a polynomial equation using the start turn radius, the end turn radius and the turning end point or the turning start point; and

steering the vehicle using a steering system along the desired path through the curve.

2. The method according to claim 1 wherein determining the desired path includes solving the polynomial equation as:

y_n(x_n)=a₀+a₁x_n+a₂x_n²+a₃x_n³+a₄x_n⁴+a₅x_n⁵,

$0\le <br><br>x_n=\frac{x}{v_x<br><br>\mathrm{\Delta <br><br>}<br><br><br><br>T}\le <br><br>1,$
y_n=y/L,

where x is vehicle longitudinal travel distance, y is vehicle lateral travel distance with respect to a current vehicle location, v_x is vehicle speed, a₀-a₅ are coefficients, L is the width of the travel lane, and Δ

T is the time for traveling through the curve.

3. The method according to claim 2 wherein determining the desired path includes determining a desired path through the curve that starts at a beginning location of the curve, has a relatively wide turn through the curve, and ends before an ending location of the curve.

4. The method according to claim 3 further comprising providing initial conditions to solve the polynomial equation at the turning start point as:

y_n(0)=0,

y′

_n(0)=0,

5. The method according to claim 3 wherein the start turn radius is R_f, the end turn radius is

6. The method according to claim 2 wherein determining the desired path includes determining a desired path through the curve that starts after a beginning location of the curve, has a relatively narrow turn through the curve, and ends at an ending location of the curve.

7. The method according to claim 6 further comprising providing initial conditions to solve the polynomial equation at the turning start point as:

y_n(0)=0,

y′

_n(0)=0,

8. The method according to claim 6 wherein the start turn radius is

9. The method according to claim 1 wherein determining the desired path includes providing a revised road curvature value of 1/R_f and a change in rate of road curvature as

10. The method according to claim 1 wherein determining a turn radius of the trailer includes determining a turn radius of a rear end of the trailer based on the turn radius of the vehicle, a wheel base of the vehicle, a distance from front wheels of the vehicle to a front bumper of the vehicle, a hitch length between the vehicle and the trailer, and a length of the trailer.

11. The method according to claim 10 wherein determining a turn radius of the rear end of the trailer includes using the equation:

R_t=√

{square root over (R_f²−

(l+a₁)²+b₁²−

b₂²)},

where R_t is the turn radius of the trailer, l is the wheel base of the vehicle, a₁ is the distance from the front bumper to the front wheels of the vehicle, b₁ is the hitch length and b₂ is the length of the trailer, and R_f is the turn radius of the vehicle and is

12. The method according to claim 1 wherein determining that the trailer will cross out of the travel lane includes comparing the turn radius of the trailer to the curvature of the curve using a width of the trailer and a width of the travel lane.

13. A method for providing vehicle steering control in an autonomously driven or semi-autonomously driven vehicle that is towing a trailer so as to prevent the trailer from crossing out of a travel lane in a curve that the vehicle is traveling along, said method comprising:

using a processor programmed for;

determining a radius of curvature of the curve, a width of the travel lane, and a length of the trailer;

determining when the vehicle has entered the curve;

determining a current steering angle of the vehicle;

determining a current turn radius of the vehicle for traveling through the curve using the current steering angle;

determining a turn radius of a rear end of the trailer using the current turn radius of the vehicle a wheel base of the vehicle, a distance from front wheels of the vehicle to a front bumper of the vehicle, a hitch length between the vehicle and the trailer, and a length of the trailer;

determining that the trailer will cross out of the travel lane based on the radius of curvature of the curve and the turn radius of the trailer;

calculating a start turn radius of the vehicle for a start location of the curve;

calculating an end turn radius of the vehicle for an end location of the curve;

determining a turning end point proximate the end location; and

determining a desired path through the curve that prevents the trailer from crossing out of the lane and that starts at a beginning location of the curve, has a relatively wide turn through the curve, and ends before an ending location of the curve using the start turn radius, the end turn radius and the turning end point, wherein determining the desired path includes providing a revised road curvature value of 1/R_f and a change in rate of road curvature as

14. The method according to claim 13 wherein determining the desired path includes solving a polynomial equation using initial and boundary conditions.

15. The method according to claim 14 wherein the initial conditions to solve the polynomial equation at the turning start point are:

y_n(0)=0,

y′

_n(0)=0,

16. The method according to claim 13 wherein the start turn radius is R_f, the end turn radius is

17. A method for providing vehicle steering control in an autonomously driven or semi-autonomously driven vehicle that is towing a trailer so as to prevent the trailer from crossing out of a travel lane in a curve that the vehicle is traveling along, said method comprising:

using a processor programmed for;

determining a radius of curvature of the curve, a width of the travel lane, and a length of the trailer;

determining when the vehicle has entered the curve;

determining a current steering angle of the vehicle;

determining a current turn radius of the vehicle for traveling through the curve using the current steering angle;

determining a turn radius of a rear end of the trailer using the current turn radius of the vehicle a wheel base of the vehicle, a distance from front wheels of the vehicle to a front bumper of the vehicle, a hitch length between the vehicle and the trailer, and a length of the trailer;

determining that the trailer will cross out of the travel lane based on the radius of curvature of the curve and the turn radius of the trailer;

calculating a start turn radius of the vehicle for a start location of the curve;

calculating an end turn radius of the vehicle for an end location of the curve;

determining a turning start point proximate the start location;

determining a desired path through the curve that prevents the trailer from crossing out of the lane and that starts after a beginning location of the curve, has a relatively narrow turn through the curve, and ends at an ending location of the curve using the start turn radius, the end turn radius and the turning start point, wherein determining the desired path includes providing a revised road curvature value of 1/R_f and a change in rate of road curvature as

18. The method according to claim 17 wherein determining the desired path includes solving a polynomial equation using initial and boundary conditions.

19. The method according to claim 18 wherein the initial conditions to solve the polynomial equation at the turning start point are:

y_n(0)=0,

y′

_n(0)=0,

20. The method according to claim 18 wherein the start turn radius is