Geolocation Estimation Using Covariance Matrices for Anchor Uncertainty
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Solution Overview
Problem
Existing localization methods face challenges in accurately determining the position of nodes in a network due to uncertainties in ranging measurements and anchor positions, particularly in collaborative navigation, where positioning errors can lead to incorrect node positioning and rejection of valid measurements.
Innovation Solution
A method that minimizes a weighted quadratic difference between ranging measurements and anchor measurements, incorporating imprecise anchor coordinates as additional measurements to jointly estimate node positions, using a heterogeneous vector of measurements and covariance matrices to account for uncertainties in both ranging and anchor measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If anchor positions are assumed to be perfectly known, then the positioning calculation is simplified, but positioning errors increase when anchor positions are actually imprecise
Solution Approach 1:
The patent changes the parameter treatment by introducing uncertainty parameters (covariance matrices) for anchor positions and transforming the fixed-anchor assumption into a probabilistic model where anchor positions are estimated alongside node positions, resolving the contradiction between calculation simplicity and positioning accuracy
Solution Approach 2:
The patent introduces a probabilistic framework with covariance matrices as an intermediary between the ranging measurements and the position estimates, allowing the system to handle imprecise anchor positions without requiring complex manual calibration or validation processes
2Adaptability or versatility
If ranging measurements are used with imprecise anchor positions, then collaborative navigation is enabled, but positioning errors propagate and may lead to rejection of valid measurements
Solution Approach 1:
The patent applies beforehand cushioning by pre-incorporating uncertainty information about anchor positions into the estimation framework through covariance matrices, which cushions the system against error propagation and prevents the rejection of valid ranging measurements that would otherwise be discarded due to anchor position uncertainties
3Quantity of substance
If absolute positioning information from GNSS is used for anchors, then anchor positions are available, but positioning errors in difficult reception conditions exceed ranging measurement errors
Solution Approach 1:
The patent merges multiple information sources (ranging measurements between nodes and absolute positioning information from GNSS for anchors) into a unified probabilistic estimation framework, where the uncertainties of each source are combined through covariance matrices to produce optimal position estimates that utilize all available information without being dominated by the less accurate GNSS anchor positions
Data Source
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AI summary
The invention relates to a global method for geolocation and the system thereof enabling estimation of the position of nodes in a network by implementing a step during which a global criterion representing all of the ranging measurements between nodes and the anchor coordinates are minimised (303), absolute position information on the kth coordinate of the node Mi obtained with an uncertainty (F). A joint estimate is performed of the coordinates of the nodes constituting the state vector by searching for the minimum in the global quadratic criterion which takes account of all of the available observations, ranging measurements and anchoring measurements, as well as the respective uncertainties of same translated by a covariance matrix over the ranging measurements and over the anchor coordinates.