Method and apparatus for providing a map matcher tolerant to wrong map features

Patent metadata

Field	Value
Publication number	US-2021095971-A1
Application number	US-202017031494-A
Country	US
Kind code	A1
Filing date	Sep 24, 2020
Priority date	Sep 27, 2019
Publication date	Apr 1, 2021
Grant date	—

Abstract

An approach is provided for providing a map matcher tolerant to wrong map features. The approach involves, for instance, finding a segment of a probe trajectory containing a plurality of low-speed probe points. The approach also involves forming a line between a first and a last probe point of the segment. The approach further involves calculating a distance from each probe point of the segment to the line. The approach further involves splitting the segment based on comparing the distance to a threshold at a turning point of the segment. The approach further involves creating a new probe trajectory based on a plurality of high-speed probe points in the probe trajectory and the turning point. The approach further involves estimating a heading of the turning point of the segment based on the new trajectory, and then performing a feasibility check between two consecutive probe points of the new trajectory.

First claim

What is claimed is:

1 . A method comprising:
finding one or more segments of a probe trajectory containing a plurality of low-speed probe points; for each segment of the one or more segments, forming a line between a first probe point and a last probe point; calculating a distance from each probe point of each segment to the line; splitting each segment based on comparing the distance to a threshold at a turning point of each segment; creating a new probe trajectory based on a plurality of high-speed probe points in the probe trajectory and the turning point of each segment; estimating a heading of the turning point of each segment based on the new trajectory; and performing a feasibility check between two consecutive probe points of the new trajectory, wherein a map matching of the new trajectory is based on the feasibility check.

2 . The method of claim 1 , further comprising:
detecting a wrong map feature in a geographic database used for the map matching based on the feasibility check.

3 . The method of claim 2 , wherein the feasibility check comprises:
classifying one or more probe points of the new trajectory as off-road based on a distance threshold from a road segment; and excluding the one or more probe points classified as off-road from the map matching.

4 . The method of claim 2 , wherein the feasibility check comprises:
calculating an angle formed by a heading of a probe point of the new trajectory and a bearing of a road segment on which the probe point is snapped; and designating the probe point as invalid based on a comparison of the angle to a threshold value.

5 . The method of claim 2 , wherein the feasibility check comprises:
determining two road segments in proximity to a probe point of the new trajectory; calculating an angle between the two road segments; classifying the two road segments as parallel based on a comparison of the angle to a threshold value; and designating one road segment of the two road segments as valid based on a proximity to the probe point.

6 . The method of claim 2 , wherein the feasibility check comprises:
determining a difference between a great-circle distance and a traveling distance between two probe points of the new trajectory; and designating a transition between the two probe points as invalid based on a comparison of the great-circle distance and the traveling distance.

7 . The method of claim 2 , wherein the feasibility check comprises:
determining a deviation between a traveling path between two probe points of the new trajectory and a line between two nodes of a road link to which the two probe points are matched; and designating a transition between the two probe points as invalid based on a comparison of the deviation to a threshold value.

8 . The method of claim 2 , wherein the feasibility check comprises:
for three consecutive probe points of the new trajectory, determining that two traveling paths share an intersection node; determining a distance between a snapped point of a second road of the intersection node; and designating a transition among the three consecutive probe points as invalid based on comparison of the distance to a threshold value.

9 . The method of claim 1 , wherein the wrong map feature includes a direction of travel, a road geometry, or a combination thereof.

10 . An apparatus comprising:
at least one processor; and at least one memory including computer program code for one or more programs, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following,
compute one or more candidate probe points for a given probe point at a selected position in a probe trajectory;
split the one or more candidate probe points into a directed set and an undirected set, wherein the directed set is based on a directed road network and wherein the undirected set is based on an undirected road network;
find one or more transitions between the one or more candidate probe points of the direct set, the undirected set, or a combination thereof; and
truncate the probe trajectory based on the one or more transitions.

11 . The apparatus of claim 10 , wherein the apparatus is further caused to:
continue map matching the probe trajectory from a trajectory position at which the probe trajectory was truncated.

12 . The apparatus of claim 10 , wherein the apparatus is further caused to:
drop the probe trajectory from map matching based on the one or more transitions.

13 . The apparatus of claim 10 , wherein the apparatus is further caused to:
determine a direction of travel over a sequence of road segments against which the probe trajectory is map matched; determine a change in the direction of travel for one road segment in the sequence; and determine a change in a restricted driving maneuver based on the change in the direction of travel.

14 . The apparatus of claim 10 , wherein the apparatus is further caused to:
map match the truncated probe trajectory to map data.

15 . The apparatus of claim 14 , wherein the apparatus is further caused to:
determine a change in road geometry, a map feature, or a combination thereof of the map data based on an invalid or an infeasible map matching.

16 . A non-transitory computer-readable storage medium carrying one or more sequences of one or more instructions which, when executed by one or more processors, cause an apparatus to at least perform the following steps:
segmenting a probe trajectory into one or more low-speed probe segments, one or more high-speed probe segments, or a combination thereof; splitting the one or more low-speed probe segments at a detected turning point; creating a new probe trajectory based on the one or more high-speed probe segments and the detected turning point of each segment of the one or more low-speed segments; and performing a feasibility check between two consecutive probe points of the new trajectory to detect a wrong map feature in map data against which the new trajectory is map matched.

17 . The non-transitory computer-readable storage medium of claim 16 , wherein the apparatus is further caused to:
generate new map data, updated map data, or a combination thereof based on the detected wrong map feature, a map matching of the new trajectory, or a combination thereof.

18 . The non-transitory computer-readable storage medium of claim 16 , wherein the apparatus is further caused to:
generate navigation guidance information based on the detected wrong map feature, a map matching of the new trajectory, or a combination thereof.

19 . The non-transitory computer-readable storage medium of claim 16 , wherein the apparatus is further caused to:
determine parking accessor data based on the detected wrong map feature, a map matching of the new trajectory, or a combination thereof.

20 . The non-transitory computer-readable storage medium of claim 16 , wherein the apparatus is further caused to:
provide an autonomous driving mode, a highly assisted driving mode, or a combination thereof based on the detected wrong map feature, a map matching of the new trajectory, or a combination thereof.

Assignees

• Here Global Bv

Inventors

• Mao Qi
• Chen Qin
• Wang Liming

Classifications

• G01C21/30 Primary

  Map- or contour-matching · CPC title

• G01C21/32 Primary

  Structuring or formatting of map data · CPC title

• G06F18/24

  Classification techniques · CPC title

• G01C21/3841

  Data obtained from two or more sources, e.g. probe vehicles · CPC title

• G01C21/3815

  Road data · CPC title