Up-Finding Trajectory Prediction for GPS-Denied Inertial Navigation
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Solution Overview
Problem
Inertial navigation systems face errors due to sporadic external aiding measurements, leading to inertial drift that corrupts navigation solutions, especially in environments without GPS signals or subject to spoofing/jamming.
Innovation Solution
A tightly coupled trajectory predictor with constant up-finding, using an up-finding sensor to provide continuous position, velocity, and attitude updates, which are integrated with inertial navigation to bound drift errors and improve navigation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If inertial navigation systems use sporadic external aiding measurements, then device complexity is reduced, but navigation accuracy deteriorates due to inertial drift
Solution Approach 1:
The patent implements continuous up-finding measurements throughout the flight trajectory, replacing sporadic external aiding measurements. The up-finder continuously provides attitude reference data to correct inertial drift, ensuring continuous navigation solution accuracy without requiring complex external aiding systems.
Solution Approach 2:
The system uses an onboard up-finder that autonomously provides attitude reference measurements without requiring external aiding infrastructure. The up-finder self-calibrates and continuously delivers navigation correction data, making the system self-sufficient and eliminating dependency on external GPS or other external aiding systems.
2Measurement precision
If continuous up-finding measurements are implemented, then navigation accuracy is improved, but device complexity increases
Solution Approach 1:
The up-finder serves multiple functions: it provides continuous attitude reference for navigation, enables trajectory prediction correction, and works across different flight phases. This multi-functionality justifies the added complexity by delivering comprehensive navigation accuracy improvements throughout the entire flight trajectory.
Solution Approach 2:
The patent integrates the up-finder measurements with the existing inertial navigation system and trajectory predictor into a unified navigation solution. The up-finder data is merged with inertial measurements and trajectory predictions, creating a tightly coupled system that achieves high accuracy without requiring separate independent systems.
3Ease of operation
If external aiding measurements are used sporadically, then system reliability is reduced, but ease of operation is improved
Solution Approach 1:
The continuous up-finding measurements provide uninterrupted navigation correction throughout flight, ensuring reliable navigation performance in GPS-denied environments. The system maintains operational simplicity while achieving reliable continuous navigation accuracy through the persistent attitude reference provided by the up-finder.
Data Source
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AI summary
Systems and methods for a tightly coupled trajectory predictor with constant up-finding are provided. In certain embodiments, a system includes an inertial measurement unit that provides inertial measurements of a vehicle. The system also includes an up-finding sensor that provides up-finding measurements based on when a portion of the vehicle is pointing up. Further, the system includes one or more processors that bound errors from the inertial measurements in a navigation solution during navigation of the vehicle using the up-finding measurements.