Moving Body Positioning Device Error Preprocessing
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Solution Overview
Problem
Existing moving body positioning systems face inaccuracies due to cumulative errors in positioning results from radio signals and geomagnetic measurements, which are not suitable for input into filters like Kalman or particle filters, as they do not resemble white noise with a mean vector of zero.
Innovation Solution
A moving body positioning apparatus that detects movement states and preprocesses positioning results to differentiate between static and dynamic conditions, ensuring data input into filters is more appropriate by characterizing errors as white noise, thereby improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If positioning results from radio signals and geomagnetic measurements are continuously input into Kalman filter or particle filter, then positioning function is maintained, but cumulative errors increase and accuracy deteriorates
Solution Approach 1:
The system performs preliminary processing of positioning results before inputting them into the filter. It calculates movement distance between consecutive positioning results and compares it with a threshold to determine whether to include each result in the filter input, preventing cumulative errors before they propagate
Solution Approach 2:
The system applies different processing rules to different positioning results based on local conditions. Positioning results are selectively accepted or rejected based on whether the movement distance exceeds the threshold, creating non-uniform quality control across the data stream
2Reliability
If positioning results obtained at the same point are repeatedly used, then high reproducibility is achieved, but offset errors are amplified and accuracy decreases
Solution Approach 1:
The system implements periodic sampling of positioning results by requiring that movement distance exceeds a threshold before accepting new data. This periodic action prevents continuous input of correlated errors from the same location while maintaining regular updates when movement occurs
Solution Approach 2:
Instead of accepting all positioning results or using traditional filtering approaches, the system inverts the selection criterion by accepting results based on movement distance thresholds rather than temporal continuity, thereby selecting a subset of results that better approximate white noise characteristics
Data Source
AI summary
In order to acquire positioning results (position and azimuth) of a moving body and reducing cumulative errors in integration processing of the positioning results, a moving body positioning apparatus includes: movement detecting means for detecting whether or not a moving body is moving; position acquiring means for acquiring a position of the moving body; integrating means for integrally processing a plurality of positions acquired by the position acquiring means as positioning results; and preprocessing means for preprocessing the positioning results to be inputted into the integrating means. In accordance with output from the movement detecting means, the preprocessing means inputs the positioning results obtained from the position acquiring means into the integrating means, which integrally processes the positioning results.