Dynamic GNSS Dead Reckoning Calibration
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Solution Overview
Problem
Conventional automotive dead reckoning systems rely on fixed weighting, which compromises positional accuracy due to inaccurate GNSS information, especially in multipath interference or jamming scenarios, leading to poor calibration and reduced accuracy in urban canyons and other areas with poor GNSS reception.
Innovation Solution
Implementing a dynamic calibration and weighting system that monitors positional accuracy from GNSS signals, allowing continuous sensor calibration only when accuracy is within an acceptable tolerance, and adjusting the reliance on dead reckoning information based on GNSS accuracy, favoring GNSS data in open sky conditions and increasing reliance on dead reckoning in areas with poor GNSS signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed weighting is used to blend dead reckoning with GNSS solutions, then the system structure is simple, but positional accuracy is compromised
Solution Approach 1:
The patent implements dynamic weighting that adjusts the reliance on dead reckoning versus GNSS solutions based on real-time assessment of GNSS signal quality. The system continuously monitors GNSS positional accuracy and adapts the blending weights dynamically, transitioning from fixed weighting to adaptive weighting to maintain optimal positional accuracy across varying signal conditions.
Solution Approach 2:
The system incorporates feedback mechanisms that continuously monitor GNSS signal quality and use this information to adjust the weighting of dead reckoning data. By feeding back the assessed signal quality to the weighting algorithm, the system automatically compensates for multipath interference and jamming conditions, improving positional accuracy without requiring complex manual configuration.
2Ease of operation
If sensor calibration is continuously updated using GNSS information, then calibration maintenance is simple, but calibration accuracy deteriorates in multipath interference or jamming scenarios
Solution Approach 1:
The system performs preliminary assessment of GNSS signal quality before initiating or continuing calibration processes. By evaluating signal characteristics in advance and only proceeding with calibration when quality thresholds are met, the system prevents inaccurate calibration updates from propagating through the navigation solution, thereby maintaining calibration accuracy without requiring complex intervention.
Solution Approach 2:
The calibration process incorporates feedback loops that monitor GNSS signal quality metrics and automatically adjust calibration update frequency and acceptance criteria. When signal quality degrades due to multipath interference or jamming, the feedback mechanism reduces or suspends calibration updates, preventing the propagation of erroneous calibration data while maintaining operational simplicity.
3Reliability
If dead reckoning is used to provide location in the absence of GNSS satellite information, then positioning availability is improved, but positional accuracy is reduced
Solution Approach 1:
The system dynamically adjusts the weighting between dead reckoning and GNSS solutions based on real-time signal quality assessment. In open-sky conditions with high GNSS accuracy, the system minimizes dead reckoning weight to preserve accuracy. In urban canyons or jamming scenarios where GNSS degrades, the system automatically increases dead reckoning weight to maintain positioning availability, creating an adaptive balance between availability and accuracy.
Solution Approach 2:
The system changes the weighting parameters of the fused navigation solution based on assessed GNSS signal quality. By dynamically adjusting these parameters in response to environmental conditions, the system optimizes the trade-off between positioning availability and accuracy, ensuring reliable operation across diverse scenarios from open sky to urban canyons.
Data Source
AI summary
A computer readable medium containing processor executable instructions configured to perform the steps of (i) monitoring a positional accuracy of location information calculated based on signals received from GNSS satellites, (ii) if the positional accuracy passes a quality check, using the location information to continuously perform a calibration of data received from one or more sensors and (iii) if the positional accuracy does not pass the quality check, cease the calibration of the data received from the sensors, wherein dead reckoning information is calculated from the data received from the sensors.