Map Matching Using Trajectory Identifiers for Ambiguous Road Segments
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Map-centric map matching techniques struggle to accurately match probe points to road segments with sufficient confidence at ambiguous locations such as crossing roads, adjacent or parallel roads, and ramps or bifurcations, leading to incorrect or low-confidence matches.
Innovation Solution
The method employs a trajectory identifier to unambiguously match probe points to either a first or second branch extending from an ambiguous link tuple by determining the number of probe points matched to each branch and assigning the probe point to the branch with the greater number of matches, or maintaining association with the ambiguous link tuple if differences are minimal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If map-centric map matching techniques are used to match probe points to road segments, then the matching speed and efficiency are improved, but the accuracy and confidence of matching at ambiguous locations deteriorate
Solution Approach 1:
The patent segments the road network into ambiguous link tuples (groups of road segments that are difficult to distinguish) and non-ambiguous road segments. By identifying and separately handling probe points at ambiguous locations through trajectory analysis, the system maintains efficient map-centric matching for most points while applying enhanced processing only where needed, thus resolving the contradiction between speed and accuracy.
Solution Approach 2:
The patent introduces trajectory identifiers as an intermediary element to resolve ambiguous matches. By analyzing the trajectory ID associated with a probe point and comparing it against trajectory patterns of previously matched probe points at the same ambiguous location, the system can disambiguate which road segment the probe point belongs to, thereby improving accuracy without sacrificing overall matching efficiency.
2Measurement precision
If probe-centric map matching techniques are used to analyze each probe point individually, then the matching accuracy is improved, but the computational cost and execution time increase substantially
Solution Approach 1:
The patent performs preliminary actions by pre-identifying and categorizing ambiguous link tuples in the road network before processing probe points. By pre-computing which road segment groups are ambiguous and storing this information, the system avoids performing expensive trajectory analyses for every probe point, instead only applying enhanced processing to probe points at pre-identified ambiguous locations, thus reducing overall computational cost while maintaining accuracy where needed.
3Reliability
If spatial searches are conducted for each probe point to identify the closest road segment, then the matching completeness is improved, but the computational expense increases proportionally with the number of probe points
Solution Approach 1:
The patent segments the road network into ambiguous link tuples and handles them differently from regular road segments. By identifying probe points at ambiguous locations through trajectory analysis and processing them separately, the system avoids conducting expensive spatial searches for all probe points, instead only performing targeted searches for ambiguous cases, thus reducing computational complexity while maintaining matching completeness.
Solution Approach 2:
The patent employs feedback mechanisms by using trajectory identifiers to provide information about the likely road segment for ambiguous probe points. This feedback from trajectory analysis reduces the need for exhaustive spatial searches, as the system can use trajectory patterns to guide and limit the search space, thereby reducing computational complexity while maintaining reliability.
Data Source
AI summary
A method, apparatus and computer program product are provided to match probe points to road segments utilizing a trajectory identifier, thereby increasing the accuracy with which probe points, such as probe points in ambiguous locations, are matched to road segments. For a probe point having a respective trajectory identifier (ID) and associated with an ambiguous link tuple, the method identifies each probe point having the respective trajectory ID that is unambiguously matched to first or second branches. The method separately determines a number of probe points having the respective trajectory ID that are unambiguously matched to the first and second branches. The method matches the probe point having the respective trajectory ID and associated with the ambiguous link tuple to either the first branch or the second branch based upon the number of probe points having the respective trajectory ID that are unambiguously matched to the first and second branches.