Automotive GNSS Positioning with Float-Fix Error Prediction
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Solution Overview
Problem
Existing GNSS receivers in vehicles suffer from inaccurate fix solutions and increased float solutions with uncertain accuracy, making centimeter positioning unreliable in automotive applications due to varying environments and lower carrier-to-noise ratios.
Innovation Solution
A positioning apparatus that includes a GNSS receiver, positioning augmentation signal receiver, and satellite positioning unit to select and process signals from multiple GNSS satellites, calculate standalone, float, and fix solutions, and predict positioning errors using integer ambiguity and error prediction methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If inexpensive GNSS receivers and antennas are used in automotive applications, then cost is reduced and device complexity is lowered, but carrier-to-noise ratios decrease and positioning accuracy deteriorates
Solution Approach 1:
The patent combines multiple positioning solutions (standalone, float, and fix solutions from multiple GNSS constellations including GPS, GLONASS, Galileo, and BeiDou) into a unified positioning system. By merging data from multiple satellites and multiple solution types, the system achieves centimeter-level accuracy using inexpensive receivers, resolving the contradiction between low cost and high precision.
Solution Approach 2:
The system dynamically changes positioning parameters by selecting between different solution types (standalone, float, fix) and different GNSS constellations based on signal quality and environmental conditions. This parameter adaptation allows the system to maintain high accuracy despite using lower-quality hardware by optimizing signal processing parameters in real-time.
2Measurement precision
If fix solutions are used for positioning, then positioning accuracy is improved to centimeter level, but mistaken fix solutions occur in varying environments causing reliability to deteriorate
Solution Approach 1:
The patent implements a feedback mechanism that continuously evaluates the quality and reliability of fix solutions by analyzing carrier-to-noise ratios, satellite geometry, and environmental conditions. When conditions indicate potential mistakes, the system provides feedback to switch to float solutions or adjust processing parameters, preventing unreliable fix solutions from degrading overall system reliability.
Solution Approach 2:
The system dynamically adapts between different positioning solution types (standalone, float, and fix solutions) based on real-time environmental conditions and signal quality. This dynamic switching allows the system to maintain reliability by avoiding fix solutions in unfavorable conditions while still achieving high accuracy when conditions permit, resolving the contradiction between accuracy and reliability.
3Measurement precision
If carrier phase positioning method is used, then positioning accuracy is improved to centimeter level, but device complexity increases due to need for multiple GNSS constellations and complex processing
Solution Approach 1:
The patent implements a universal positioning system that processes multiple GNSS constellations (GPS, GLONASS, Galileo, BeiDou) and multiple solution types (standalone, float, and fix solutions) through a single integrated processing framework. This multi-functional approach achieves centimeter-level accuracy without requiring separate specialized systems for each constellation or solution type, reducing overall device complexity while maintaining high precision.
4Reliability
If float solutions are used instead of fix solutions, then reliability is improved by avoiding mistaken solutions, but positioning accuracy deteriorates to meter level
Solution Approach 1:
The patent merges float solutions from multiple GNSS constellations and multiple frequency bands into a combined positioning result. By combining the more reliable float solutions from diverse satellite sources, the system achieves both improved reliability (avoiding mistaken fix solutions) and maintained accuracy (through aggregated data from multiple constellations), resolving the contradiction between reliability and precision.
Data Source
AI summary
The object is to provide a technology for appropriately making the centimeter positioning available in automotive applications. A positioning apparatus determines a standalone positioning solution including a vehicle position, determines a float solution including the vehicle position and a carrier phase bias, determines an integer ambiguity, determines a fix solution including the vehicle position, sets any one of the standalone positioning solution, the float solution, the fix solution, and a non-positioning solution indicating no existence of a solution as a positioning solution, and predicts a positioning error of the positioning solution as a positioning error of the vehicle position per epoch.