Inertial Navigation Alignment via Multi-Duration Consistency Checks
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Solution Overview
Problem
Current inertial navigation systems face challenges in accurately aligning static or quasi-static carriers due to low-frequency oscillatory movements, which degrade the initialization accuracy and result in significant inertial drift, especially when using limited accuracy inertial sensors.
Innovation Solution
Implementing a method where multiple alignment processes with distinct observation durations are conducted simultaneously, and the consistency of alignment information is confirmed through inter-alignment consolidation, allowing for the selection of the minimum observation duration with confirmed consistency, thereby reducing inertial drift and improving alignment soundness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single alignment process with fixed observation duration is used, then the alignment procedure is simple, but inertial drift increases due to low-frequency oscillatory movements degrading initialization accuracy
Solution Approach 1:
The alignment process is segmented into multiple parallel alignment processes, each with distinct observation durations (e.g., first, second, and third alignment processes with different durations). This segmentation allows the system to handle low-frequency oscillatory movements by distributing the alignment task across multiple time scales, thereby improving reliability without requiring a single overly complex prolonged process.
Solution Approach 2:
The system dynamically selects which alignment process results to use based on consistency checks. The alignment process adapts to actual carrier movement conditions by comparing results from multiple parallel processes and selecting the most reliable ones, making the overall system dynamic rather than static.
2Measurement precision
If multiple alignment processes with distinct observation durations are implemented simultaneously, then inertial drift is minimized and alignment accuracy is improved, but the alignment process complexity increases
Solution Approach 1:
The system implements feedback through consistency checks that compare alignment results from multiple parallel processes. The fourth alignment process performs consistency checks on results from the first three alignment processes, and the fifth alignment process performs consistency checks on results from the fourth alignment process and previous alignment results. This feedback mechanism ensures that only accurate alignment information is selected, improving measurement precision while managing complexity through systematic verification.
Solution Approach 2:
The system changes the observation duration parameter across different alignment processes (first, second, and third alignment processes have distinct observation durations). This parameter variation allows the system to capture alignment information at different time scales, improving the ability to filter out low-frequency oscillatory movements and enhance initialization accuracy.
3Reliability
If alignment information from multiple processes is consolidated, then the soundness of alignment is confirmed and drift is reduced, but the processing time and complexity increase
Solution Approach 1:
The system performs preliminary alignment processes (first, second, and third alignment processes) simultaneously with distinct observation durations before final consolidation. This preliminary action allows the system to pre-process alignment information from multiple time scales, so that when consistency checks are performed, the most reliable results are already prepared, reducing the time needed for final validation and selection.
Solution Approach 2:
The system implements a hierarchical consistency check structure where the fourth alignment process checks consistency of results from the first three processes, and the fifth alignment process checks consistency of the fourth process results with previous alignment results. This partial verification approach (checking consistency at multiple hierarchical levels rather than exhaustive verification) confirms alignment soundness while managing processing time efficiently.
Data Source
AI summary
The invention relates to a method for aligning an inertial navigation system borne by a static or quasi-static carrier, wherein: a plurality of alignment processes that are dimensioned for a plurality of amplitudes of movements of the carrier are implemented simultaneously with different alignment observation durations; a minimum observation duration that corresponds to the alignment observation duration for which the consistency of the alignment information obtained by means of alignment processes dimensioned for a given movement amplitude of the carrier is determined; and the alignment information is determined depending on alignment information determined for this minimum observation duration. The invention also relates to an associated inertial navigation system.