Adaptive path following algorithm for heavy-duty vehicles

Patent metadata

Field	Value
Publication number	US-12377845-B2
Application number	US-202218561358-A
Country	US
Kind code	B2
Filing date	May 23, 2022
Priority date	May 25, 2021
Publication date	Aug 5, 2025
Grant date	Aug 5, 2025

Abstract

A method for controlling a heavy-duty vehicle to follow a reference path (P), comprising determining a goal point along the reference path to be used as a steering reference from a vehicle location in vicinity of the path, where the goal point is distanced along the path by a preview distance measured from a reference location associated with the vehicle location, determining a direction w 1 of a first flow field associated with the reference path, determining whether a lateral deviation of the vehicle location from the reference path exceeds a threshold lateral deviation, and controlling the vehicle in accordance with the direction w 1 of a first flow field if the lateral deviation exceeds the threshold lateral deviation, and otherwise controlling the vehicle in accordance with the direction w pipe of a pipe flow substantially parallel to the reference path or in accordance with an optimization-based path.

First claim

The invention claimed is:

1. A method for controlling a heavy-duty vehicle to follow a reference path (P), the method comprising:
obtaining the reference path (P) to be followed by the vehicle,
determining a goal point (G) along the reference path (P) to be used as a steering reference from a vehicle location (x) in vicinity of the path (P), where the goal point (G) is distanced along the path (P) by a preview distance (Dp) measured from a reference location (x, G 0 ) associated with the vehicle location (x),
determining, on the basis of the goal point (G), a direction w 1 of a first flow field associated with the reference path (P),
determining whether a lateral deviation (y) of the vehicle location (x) from the reference path (P) exceeds a threshold lateral deviation (y max ), and
controlling the vehicle in accordance with the direction w 1 of a first flow field if the lateral deviation (y) exceeds the threshold lateral deviation (y max ), and otherwise controlling the vehicle in accordance with the direction w pipe of a pipe flow substantially parallel to the reference path (P) or in accordance with an optimization-based path.

2. The method of claim 1 , wherein the pipe flow is parallel to the reference path (P) in at least a first segment of the reference path (P).

3. The method of claim 1 , wherein the first flow field is a continuous function with respect to the lateral deviation (y) and its direction w 1 is oriented parallel to the reference path (P) at or near the threshold lateral deviation (y max ).

4. The method of claim 2 , wherein the pipe flow has a nonzero centripetal component in at least a second segment of the reference path (P), wherein the second segment corresponds to where the reference path's curvature (κ) exceeds a threshold curvature.

5. The method of claim 1 , wherein the optimization-based path is determined using a cost function that penalizes acceleration above a threshold acceleration.

6. The method of claim 1 , wherein the optimization-based path is determined by minimizing total travel time.

7. The method of claim 1 , wherein the optimization-based path is determined by minimizing a norm of a second derivative of the path's curvature.

8. The method of claim 1 , wherein the optimization-based path is determined by fitting a low-degree polynomial to the reference path (P).

9. The method of claim 1 , wherein the optimization-based path is determined subject to a constraint of not exceeding the threshold lateral deviation (y max ).

10. The method of claim 1 , wherein the optimization-based path is determined by optimizing a cost function over possible paths extending up to a nonzero forward horizon (D opt ).

11. The method of claim 1 , wherein the direction w 1 of the first flow field is determined as

w
1

=

t
3

+

t
1

-

t
2

2
⁢
cos
⁢
θ

where t 1 is a unit-length tangent vector to the reference path (P) evaluated at the reference location (G 0 ), t 2 is a unit-length tangent vector to the reference path (P) evaluated at the goal point (G), t 3 is a unit-length vector directed from the vehicle location (x) towards the goal point (G), and angle θ is half the angle between the two tangent vectors t 1 and t 2 .

12. The method of claim 1 , wherein the preview distance (D p ) is variable.

13. The method of claim 12 , wherein the preview distance (D p ) increases with an increasing lateral deviation (y) from the reference path (P), and decreases with a decreasing lateral deviation (y).

14. The method of claim 1 , wherein the reference location (x) equals the vehicle location.

15. The method of claim 1 , wherein the reference location (G 0 ) is a location on the path (P) intersected by a straight line orthogonal to the path (P) at the reference location (G 0 ) through the vehicle location (x).

16. The method of claim 1 , wherein controlling the vehicle comprises performing a Lane Keep Assistance function, a semi-autonomous drive application, or an autonomous drive application.

17. A control unit for controlling a heavy-duty vehicle to follow a reference path (P), the control unit comprising processing circuitry configured to perform the method claim 1 .

18. A heavy-duty vehicle comprising the control unit of claim 17 .

Assignees

• Volvo Truck Corp

Inventors

• Gao Yangyan
• Gordon Timothy
• Rahman Shammi
• Henderson Leon

Classifications

• B60W2510/20

  Steering systems · CPC title

• B60W2520/125

  Lateral acceleration · CPC title

• B60W2300/125

  Heavy duty trucks · CPC title

• B60W30/045

  Improving turning performance · CPC title

• B60W2552/30

  Road curve radius · CPC title