Ambiguity Map Match Rating for Navigation Accuracy
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Solution Overview
Problem
Navigation systems face errors in positional data due to obstructions and multipath effects, leading to inaccurate map matching, which can result in severe consequences for both mapping services and end users.
Innovation Solution
A method is provided to determine an ambiguity rating for road segments based on their relationships with neighboring segments, allowing for the selection of appropriate map matching algorithms to improve accuracy and efficiency in map matching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex algorithms with multiple inputs are used for map matching, then accuracy is improved, but device complexity increases
Solution Approach 1:
The system performs preliminary analysis of the road network geometry and GPS error characteristics before map matching to identify high-ambiguity areas. Ambiguity ratings are pre-calculated and stored for road segments, allowing the system to know in advance which areas require complex algorithms and which can use simple algorithms, thus avoiding unnecessary computational complexity in low-ambiguity areas.
Solution Approach 2:
The system applies different map matching algorithm complexities based on local characteristics of road segments. High-ambiguity segments (identified by ambiguity ratings) use complex algorithms with multiple inputs, while low-ambiguity segments use simple algorithms. This local adaptation ensures high accuracy where needed while minimizing overall computational complexity.
2Device complexity
If simple map matching algorithms are used, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The system dynamically changes the parameter of algorithm complexity based on the ambiguity rating of the current road segment. When the ambiguity rating indicates high potential for errors (e.g., parallel roads, dense networks), the system switches to complex algorithms. When the rating is low, simple algorithms suffice. This parameter adaptation optimizes the balance between complexity and precision.
Solution Approach 2:
The map matching system is dynamic in selecting algorithm complexity rather than using a fixed approach. The ambiguity rating serves as a dynamic indicator that triggers appropriate algorithm selection in real-time based on the current geographic context, ensuring precision is maintained only where necessary.
3Loss of information
If GPS signals are used in obstructed areas, then position data is obtained, but measurement precision deteriorates due to multipath and satellite blockage
Solution Approach 1:
The system prepares for potential GPS errors by pre-calculating ambiguity ratings for all road segments based on their geometric characteristics and error susceptibility. This beforehand preparation creates a cushion against GPS inaccuracies by having pre-identified high-risk areas where enhanced verification is needed, compensating for the inherent imprecision in obstructed signal environments.
Data Source
AI summary
Methods and apparatuses are provided for generating, using, and storing ambiguity ratings for map matching. In an embodiment, an ambiguity rating is generated using a road segment and a relationship of the road segment and other nearby road segments. The ambiguity rating may be stored in a cell based map. The ambiguity rating may be used to select an efficient map matching algorithm and provide expected map matching confidence.