IP Library Granted Patent US 12676012
Granted Patent B2
US 12676012 · App. 18/471,712 · Granted Jul 7, 2026

System and method for lane graph estimation

Inventor: Alexander Christoph Schaefer (Fremont, CA)
Assignee: Toyota Jidosha Kabushiki Kaisha
G06V20/588
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Quick Facts
Patent No.
US 12676012
App. No.
18/471,712
Granted
Jul 7, 2026
Kind
B2
Abstract

Systems, methods, and other embodiments described herein relate to estimating a lane graph describing a road portion. In one embodiment, a method includes receiving a frame graph of a road portion. The frame graph has a plurality of cycles, and each cycle is an enclosed configuration of three or more edges. Each edge connects two trace points. Further, each edge has one or more relationship options between the two trace points and a probability value for each of the one or more relationship options. Each trace point is related to a position of a vehicle in the road portion. The method includes estimating, using a maximum likelihood estimation (MLE) process, a lane graph describing the road portion based on at least a portion of the frame graph.

Claims (51)

1 . A system comprising:

a processor; and

a memory storing machine-readable instructions that, when executed by the processor, cause the processor to:

receive a frame graph of a road portion, the frame graph having a plurality of cycles, each cycle being an enclosed configuration of three or more edges, each edge connecting two trace points, each edge having one or more relationship options between the two trace points and a probability value for each of the one or more relationship options, each of the one or more relationship options including trace points in a same lane, trace points in adjacent lanes leftward, and trace points in adjacent lanes rightward, each trace point being related to a position of a vehicle in the road portion;

estimate, using a maximum likelihood estimation process, a lane graph describing the road portion based on at least a portion of the frame graph; and

operate a vehicle control system based on the lane graph, the vehicle control system being at least one of a steering system, a braking system, and a transmission system.

2 . The system of claim 1 , wherein the machine-readable instructions for estimating the lane graph further include instructions that when executed by the processor cause the processor to:

determine validity of at least one of the plurality of cycles based on the three or more edges of the at least one of the plurality of cycles.

3 . The system of claim 2 , wherein the machine-readable instructions further include instructions that when executed by the processor cause the processor to:

identify, in response to the at least one of the plurality of cycles being invalid, one of the three or more edges that is likely to be invalid; and

discard the one of the three or more edges that is likely to be invalid.

4 . The system of claim 2 , wherein the machine-readable instructions further include instructions that when executed by the processor cause the processor to:

identify, in response to the at least one of the plurality of cycles being invalid, one of the three or more edges that is likely to be invalid;

select an other relationship option for the one of the three or more edges that is likely to be invalid; and

determine validity of at least one of the plurality of cycles based on the one of the three or more edges that is likely to be invalid having the other relationship option.

5 . The system of claim 1 , wherein the machine-readable instructions for estimating the lane graph further include instructions that when executed by the processor cause the processor to:

determine validity of at least one of the plurality of cycles based on the three or more edges of the at least one of the plurality of cycles and at least one neighboring cycle that shares at least one of the three or more edges.

6 . The system of claim 1 , wherein the machine-readable instructions for estimating the lane graph further include instructions that when executed by the processor cause the processor to:

determine a best fit for at least a portion of the plurality of cycles based on the three or more edges of at least the portion of the plurality of cycles.

7 . A method comprising:

receiving a frame graph of a road portion, the frame graph having a plurality of cycles, each cycle being an enclosed configuration of three or more edges, each edge connecting two trace points, each edge having one or more relationship options between the two trace points and a probability value for each of the one or more relationship options, each of the one or more relationship options including trace points in a same lane, trace points in adjacent lanes leftward, and trace points in adjacent lanes rightward, each trace point being related to a position of a vehicle in the road portion;

estimating, using a maximum likelihood estimation process, a lane graph describing the road portion based on at least a portion of the frame graph; and

operating a vehicle control system based on the lane graph, the vehicle control system being at least one of a steering system, a braking system, and a transmission system.

8 . The method of claim 7 , wherein estimating the lane graph includes:

determining validity of at least one of the plurality of cycles based on the three or more edges of the at least one of the plurality of cycles.

9 . The method of claim 8 , further comprising:

identifying, in response to the at least one of the plurality of cycles being invalid, one of the three or more edges that is likely to be invalid; and

discarding the one of the three or more edges that is likely to be invalid.

10 . The method of claim 8 , further comprising:

identifying, in response to the at least one of the plurality of cycles being invalid, one of the three or more edges that is likely to be invalid;

selecting an other relationship option for the one of the three or more edges that is likely to be invalid; and

determining validity of at least one of the plurality of cycles based on the one of the three or more edges that is likely to be invalid having the other relationship option.

11 . The method of claim 7 , wherein estimating the lane graph includes:

determining validity of at least one of the plurality of cycles based on the three or more edges of the at least one of the plurality of cycles and at least one neighboring cycle that shares at least one of the three or more edges.

12 . The method of claim 7 , wherein estimating the lane graph includes:

determining a best fit for at least a portion of the plurality of cycles based on the three or more edges of at least the portion of the plurality of cycles.

13 . A non-transitory computer-readable medium including instructions that when executed by a processor cause the processor to:

receive a frame graph of a road portion, the frame graph having a plurality of cycles, each cycle being an enclosed configuration of three or more edges, each edge connecting two trace points, each edge having one or more relationship options, each of the one or more relationship options including trace points in a same lane, trace points in adjacent lanes leftward, and trace points in adjacent lanes rightward, each trace point being related to a position of a vehicle in the road portion;

estimate, using a maximum likelihood estimation process, a lane graph describing the road portion based on at least a portion of the frame graph; and

operate a vehicle control system based on the lane graph, the vehicle control system being at least one of a steering system, a braking system, and a transmission system.

14 . The non-transitory computer-readable medium of claim 13 , wherein the instructions for estimating the lane graph further include instructions that when executed by the processor cause the processor to:

determine validity of at least one of the plurality of cycles based on the three or more edges of the at least one of the plurality of cycles.

15 . The non-transitory computer-readable medium of claim 14 , wherein the instructions further include instructions that when executed by the processor cause the processor to:

identify, in response to the at least one of the plurality of cycles being invalid, one of the three or more edges that is likely to be invalid; and

discard the one of the three or more edges that is likely to be invalid.

16 . The non-transitory computer-readable medium of claim 14 , wherein the instructions further include instructions that when executed by the processor cause the processor to:

identify, in response to the at least one of the plurality of cycles being invalid, one of the three or more edges that is likely to be invalid;

select an other relationship option for the one of the three or more edges that is likely to be invalid; and

determine validity of at least one of the plurality of cycles based on the one of the three or more edges that is likely to be invalid having the other relationship option.

17 . The non-transitory computer-readable medium of claim 13 , wherein the instructions for estimating the lane graph further include instructions that when executed by the processor cause the processor to:

determine validity of at least one of the plurality of cycles based on the three or more edges of the at least one of the plurality of cycles and at least one neighboring cycle that shares at least one of the three or more edges.