Map Matching Apparatus Using Pressure Sensor Altitude Validation
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Solution Overview
Problem
Existing map matching technologies face challenges in accurately determining the current position on a road map, especially when GPS reception is poor, leading to potential backward movement misinterpretation and increased processing complexity.
Innovation Solution
A map matching apparatus that includes a processor, map storage unit, and sensors (GPS, terrestrial-magnetism, acceleration, and pressure sensors) to measure and validate the current position, using altitude information from pressure sensors to complement GPS data and determine correct road position matching, thereby simplifying the determination process and reducing processing load.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS reception is used for position measurement, then position information can be obtained, but accuracy deteriorates in poor reception environments
Solution Approach 1:
The patent combines multiple position measurement techniques (GPS, map matching, and alternative methods) into a unified system. When GPS reception is poor, the system seamlessly transitions to using map matching based on vehicle speed and direction from sensors, ensuring continuous accurate position tracking without relying solely on GPS
Solution Approach 2:
The system dynamically changes measurement parameters by switching between GPS-based positioning and map matching based positioning according to reception conditions. When GPS accuracy falls below a threshold, the system transitions to using sensor data (accelerometer, gyroscope, magnetometer) combined with map data to calculate position, maintaining measurement precision despite poor GPS reception
2Measurement precision
If complex determination processing is performed to verify candidate road positions, then matching accuracy improves, but processing complexity increases
Solution Approach 1:
The system performs preliminary filtering of candidate road positions based on basic criteria (proximity to measured position, road orientation consistency) before conducting more detailed verification. This preliminary action reduces the number of candidates requiring complex determination processing, thereby reducing overall processing complexity while maintaining accuracy
Solution Approach 2:
The patent replaces complex mechanical determination processes with computational methods. Instead of exhaustive verification of all candidate positions, the system uses algorithmic approaches comparing sensor data with map data to efficiently determine the correct road position, reducing processing complexity through information processing rather than mechanical verification
3Measurement precision
If continuous position measurement and verification is performed, then position accuracy is maintained, but power consumption increases
Solution Approach 1:
The system performs position measurement and verification periodically rather than continuously. It updates position information at intervals based on changes in vehicle state (speed, direction) or environmental conditions (GPS reception quality), maintaining measurement precision while significantly reducing power consumption compared to continuous monitoring
Solution Approach 2:
The system uses self-service by leveraging existing sensor data (from vehicle's own sensors like accelerometers and gyroscopes) and pre-stored map data to perform map matching without requiring additional active measurement components. This approach maintains position accuracy while minimizing power consumption by reusing available resources
4Reliability
If multiple candidate road positions are evaluated, then matching reliability improves, but processing time increases
Solution Approach 1:
The determination process is segmented into multiple stages: initial candidate generation, preliminary filtering based on basic criteria, and detailed verification of remaining candidates. This segmentation allows the system to evaluate multiple candidates systematically, improving reliability by thorough evaluation while reducing processing time by eliminating candidates early in the process rather than performing complete verification on all of them
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate map matching even with low GPS accuracy, simplifies determination processing, and reduces power consumption, preventing unnecessary backward movement displays by using altitude information to validate position accuracy.
Implementation Method 1
A map matching apparatus that includes a processor, map storage unit, and sensors (GPS, terrestrial-magnetism, acceleration, and pressure sensors) to measure and validate the current position, using altitude information from pressure sensors to complement GPS data
Data Source
AI summary
In a map matching apparatus, a processor executes, by the program stored in a storage unit, position measurement processing of measuring a current position, matching processing of performing, based on the current position measured in the position measurement processing, matching with a corresponding road position in the road map data stored in the map storage unit, determination processing of determining whether a candidate of a road position to be matched in the matching processing is correct or not, and matching control processing of setting, based on a determination result of the determination processing, the candidate of the road position to be matched in the matching processing.