Position Detection System Multipath Error Reduction
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Solution Overview
Problem
Existing position detection systems using high-frequency signals face accuracy issues due to multipath effects when measuring distances between master and slave devices.
Innovation Solution
The system measures distances multiple times to obtain minimum values, calculates intersection points of arcs with these minimum values, and uses the center of gravity of intersection points as the true position when distances are within a predetermined value, thereby reducing multipath effects and enhancing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-frequency signals are used to measure distances between master device and slave devices, then measurement speed and resolution are improved, but measurement precision deteriorates due to multipath effects
Solution Approach 1:
The system performs multiple preliminary distance measurements before final position calculation. By measuring distances multiple times and selecting the minimum value, the system proactively identifies and excludes multipath-affected measurements before they can corrupt the final position result, thus resolving the contradiction between using high-frequency signals and avoiding multipath errors.
Solution Approach 2:
The system uses feedback from multiple distance measurements to identify and correct multipath errors. By comparing multiple measured distance values and selecting the minimum, the system creates a feedback mechanism that automatically identifies and excludes measurements corrupted by multipath effects, thereby maintaining measurement precision despite the presence of harmful multipath factors.
2Measurement precision
If multiple distance measurements are performed to exclude multipath effects, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The system performs multiple distance measurements as a preliminary step to establish reliable distance data before final position calculation. By pre-identifying the minimum distance value from multiple measurements, the system prepares accurate input data in advance, ensuring position measurement accuracy while managing the time investment through efficient selection of the minimum value.
Solution Approach 2:
The system discards distance measurements that are likely affected by multipath effects (identified as non-minimum values) and recovers the accurate position information from the remaining valid measurements. This selective discarding of corrupted data and recovery of clean data enables precise position measurement without requiring all measurements to be perfectly accurate, thus reducing the time penalty.
3Measurement precision
If intersection points of arcs are used to determine slave device position, then position accuracy is improved, but device complexity increases due to multiple calculation processes
Solution Approach 1:
The position determination process is segmented into distinct stages: first measuring distances from multiple master devices, then calculating arcs based on these distances, finding intersection points of these arcs, and finally determining position from the intersection points. This segmentation of the calculation process into manageable stages improves position accuracy through systematic geometric construction while making the overall complex process more structured and implementable.
Solution Approach 2:
The system introduces intermediate geometric constructs (arcs and their intersection points) as mediators between the raw distance measurements and the final position determination. These intermediate elements serve as a bridge that transforms distance data into position information through well-defined geometric relationships, improving accuracy while organizing the calculation complexity into standard geometric operations.
Data Source
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AI summary
In order to provide a position detection system that can measure, with a high accuracy, distances between a slave device and master devices and a position of the slave device, even when using high-frequency signals, a position detection system 100 that measures a position of the slave device 180 using high-frequency signals includes a plurality of parent devices 110-140 surrounding a measurement area 101, and a slave device 180 positioned in the measurement area 101. The position detection system 100 executes a first process that measures distances D11-D14 between the slave device 180 and each of the plurality of master devices 110-140 a plurality of times, to obtain a minimum value of each of the distances D11-D14, a second process that obtains a position of an intersection point P1-P4 of two arcs among a plurality of arcs 117-147 respectively having the minimum value of each of the distances as a radius from respective centers of the plurality of master devices 110-140 when a number of intersection points of the two arcs within the measurement area 101 is one, and a third process that regards a center of gravity of the plurality of intersection points P1-P4 as a true position of the slave device 180 when distances among the plurality of intersection points P1-P4 are less than a predetermined value.