Odometry Integrity Monitoring via Solution Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing navigation systems face challenges in ensuring the integrity of odometry measurements, particularly in environments where GNSS measurements are unreliable, and in detecting faults in sensors used for navigation, which can impact the accuracy and reliability of vehicle positioning and orientation.
Innovation Solution
A system that incorporates imaging sensors to generate odometry information, which is then combined with GNSS pseudorange measurements to calculate full and sub-solutions, allowing for the determination of measurement integrity through a solution separation methodology, enabling the detection of faults and computation of protection levels for navigation system reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solution separation methodology is used to monitor integrity of odometry measurements, then measurement integrity and fault detection capability are improved, but device complexity and computational load increase
Solution Approach 1:
The patent applies segmentation by dividing the measurement set into multiple subsets and calculating separate solutions for each subset. The integrity monitoring is achieved by comparing these segmented solutions against each other and against the full solution, allowing fault detection without requiring a single complex integrity monitoring system.
Solution Approach 2:
The patent uses the difference between sub-solutions and full solution as an intermediary indicator of measurement integrity. By comparing these solutions, the system can detect faults in odometry measurements without directly measuring integrity, using the solution differences as a mediator to infer measurement health.
2Measurement precision
If multiple sub-solutions are calculated for integrity monitoring, then fault detection accuracy is improved, but processing time and computational resources increase
Solution Approach 1:
The patent calculates a limited number of sub-solutions (exactly two sub-solutions) rather than exhaustively calculating all possible combinations. This partial action provides sufficient fault detection accuracy while avoiding excessive computational time, as the patent demonstrates that two sub-solutions are adequate for monitoring odometry measurement integrity.
3Reliability
If odometry information from imaging sensors is used to supplement GNSS measurements, then navigation reliability in GNSS-denied environments is improved, but susceptibility to sensor faults and measurement errors increases
Solution Approach 1:
The patent implements feedback by continuously monitoring the consistency between sub-solutions and the full solution, and using this feedback to detect faults in odometry measurements. When inconsistencies exceed thresholds, the system can identify and exclude faulty measurements, allowing safe use of odometry information while protecting against sensor faults.
Data Source
AI summary
Systems and methods for integrity monitoring of odometry measurements within a navigation system are provided herein. In certain embodiments, a system includes imaging sensors that generate image frames from optical inputs. The system also includes a GNSS receiver that provides pseudorange measurements; and computational devices that receive the image frames and the pseudorange measurements. Further, the computational devices compute odometry information from image frames acquired at different times; and calculate a full solution for the system based on the pseudorange measurements and the odometry information. Additionally, the computational devices calculate sub-solutions for the system based on subsets of the pseudorange measurements and the odometry information, wherein one of the sub-solutions is not based on the odometry information. Moreover, the computational device determines the integrity of the pseudorange measurements, the odometry information, and a position estimated by the navigation system based on a comparison of the full and sub-solutions.