Vehicle Terminal Device Positioning Accuracy via Mismatch Filtering
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Solution Overview
Problem
Existing vehicle positioning systems face accuracy deterioration due to disturbances in travel and reference locus information, leading to mismatch issues that affect position estimation accuracy.
Innovation Solution
A terminal device with a communication state obtain unit, travel locus information generation unit, reference locus information obtain unit, measurement unit, mismatch detection unit, and filtering unit that filters travel and reference locus information based on mismatch and its cause to improve position estimation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If filtering is applied to travel locus information or reference locus information, then position estimation accuracy is improved, but device complexity increases
Solution Approach 1:
The patent applies different filtering methods (low-pass filter, high-pass filter, band-pass filter, median filter) based on the detected cause of mismatch. By changing the filtering parameter according to the mismatch cause, the system improves position estimation accuracy while managing processing complexity through selective application.
Solution Approach 2:
The system performs mismatch detection and filtering before position estimation. By preliminarily filtering the travel locus information or reference locus information based on detected mismatch causes, the system prepares cleaner data for estimation, improving accuracy while avoiding more complex post-processing.
2Measurement precision
If mismatch detection and filtering are performed, then position estimation accuracy is improved, but processing time increases
Solution Approach 1:
The system applies filtering selectively based on the detected mismatch cause. Instead of uniformly processing all data, it applies specific filtering methods only where needed (e.g., low-pass filter for high-frequency noise, median filter for impulse noise), improving accuracy while minimizing unnecessary processing time.
Solution Approach 2:
The processing is divided into distinct stages: mismatch detection, cause identification, and selective filtering. This segmentation allows the system to efficiently process only the necessary portions of data with appropriate methods, reducing overall processing time while maintaining accuracy.
Data Source
AI summary
A terminal device includes a communication state obtain unit that obtains a state of wireless communication, a travel locus information generation unit that generates travel locus information, a reference locus information obtain unit that obtains reference locus information, a measurement unit that obtains a position of a movable body along a travel direction based on a matching between the travel locus information and the reference locus information, a mismatch detection unit that detects at least one of (i) mismatch degree between the travel locus information and the reference locus information in the matching, and (ii) a cause of mismatch in the matching, and a filtering unit that filters at least one of the travel locus information and the reference locus information. The measurement unit performs the matching before the filtering, which increases the measurement accuracy of the terminal device.