Single-Difference Pre-Filter for GNSS Sensor Integrity
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Solution Overview
Problem
Existing navigation systems face challenges in reliably monitoring the health and integrity of sensors, particularly in safety-critical applications, due to unpredictable common errors in measurements such as those from GNSS receivers.
Innovation Solution
The implementation of an auxiliary filter that calculates a single difference in measurements and applies innovation sequence monitoring to identify faulty measurements, which are then excluded from the solution separation algorithm to ensure accurate navigation data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solution separation method is used to monitor sensor integrity, then measurement reliability is improved, but common errors in measurements cannot be effectively removed
Solution Approach 1:
The patent applies preliminary action by performing single difference calculations on measurements before they are processed by the solution separation algorithm. This pre-processing step removes common errors from the measurements in advance, so that when the solution separation method subsequently processes the cleaned measurements, both reliability and precision are improved without contradiction
2Reliability
If redundancy in sensor measurements is exploited for fault detection, then measurement integrity is improved, but common errors affecting multiple sensors cannot be identified
Solution Approach 1:
The patent extracts common errors from the measurement set by calculating single differences between measurements. This operation isolates and removes the common error component that affects multiple sensors, allowing the solution separation algorithm to subsequently detect faults based on individual sensor anomalies rather than being confounded by shared errors
Data Source
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AI summary
Systems and methods for a single-difference based pre-filter of measurements for use in solution separation framework are provided. In certain embodiments, a navigation system includes at least one receiver configured to receive a plurality of signals transmitted from a plurality of transmitters. The navigation system further includes a processing unit operatively coupled to the navigation system, the processor configured to identify a plurality of measurements associated with the plurality of transmitters. Additionally, executable instructions cause the processing unit to calculate an auxiliary navigation solution based on a calculated single difference between the plurality of measurements; calculate one or more single difference residuals for the auxiliary navigation solution; perform statistical tests on the one or more single difference residuals; and to identify a set of measurements in the plurality of measurements for use in a solution separation method based on the statistical tests.