Pathway Matching for Indoor Mobile Device Location Estimation
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Solution Overview
Problem
Conventional mobile devices struggle to determine location accurately in areas where GPS signals are weak or unavailable, such as indoors or in tunnels, due to strict constraints imposed by pathways, leading to large estimation errors and increased uncertainty.
Innovation Solution
The method involves using pathway matching with a state space model to estimate the location of a mobile device by propagating candidate locations based on sensor readings and pathway constraints, allowing for elasticity in matching to model pedestrian behavior more accurately and improve location estimation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If strict pathway constraints are imposed for location estimation, then location accuracy is improved, but estimation uncertainty increases and real-life pedestrian behavior is not accurately modeled
Solution Approach 1:
The patent applies dynamics by making the pathway constraint flexible rather than rigid. Candidate locations are dynamically adjusted based on their proximity to pathway segments, with the constraint strength varying by distance. This allows the system to adapt to real-life pedestrian behavior where people may occasionally deviate from pathways, while still maintaining accurate location estimation when pedestrians are near or on pathways.
2Measurement precision
If GPS receiver is used for location determination, then location can be obtained in open areas, but location determination fails in areas with weak or no GPS signals such as indoors or tunnels
Solution Approach 1:
The patent introduces pathway segments as an intermediary between the mobile device and the location determination process. Instead of relying directly on GPS signals, the system uses pathway matching as a mediator to estimate location based on the device's proximity to known pathway segments. This intermediary approach enables location determination in areas where GPS signals are unavailable, such as indoors or in tunnels.
3Measurement precision
If candidate locations are mapped strictly to pathway segments, then location estimation accuracy is improved, but flexibility in modeling pedestrian behavior is reduced
Solution Approach 1:
The patent changes the parameter of constraint strictness by introducing a distance-based mapping approach. Candidate locations are mapped to pathway segments based on their proximity, with the mapping strength varying as a parameter function of distance. This parameter change allows the system to maintain high location estimation accuracy for candidates near pathways while preserving behavioral flexibility for candidates farther away, accurately reflecting real-life pedestrian behavior.
Data Source
AI summary
Methods, program products, and systems for estimating a location of a mobile device in a venue are provided. The venue can have pathways represented by a path network that includes segments connected by junctions. Estimating the location can include determining a first set of candidate locations for the mobile device, and mapping some of the candidate locations to updated candidate locations that are on or closer to one or more segments of the path network based on distances between the candidate locations and respective segments, resulting in a second set of candidate locations for the mobile device. The location of the mobile device can be derived from the second set of candidate locations.