Mobile Device Position Estimation Using Annular Area Overlap
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing mobile device position estimation systems face inaccuracies due to reception signal intensity errors, resulting in large areas of uncertainty for the mobile device's location, which affects the precision of position estimation.
Innovation Solution
A mobile device position estimation system that includes in-vehicle devices with multiple antennas and a mobile device equipped with a reception intensity detection portion, sensitivity error decision portion, annular area decision portion, and area estimation portion, which corrects reception signal intensity errors to narrow the detection areas and estimate the overlapping area as the mobile device's existence area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If position estimation is performed based on reception signal intensity from three or more in-vehicle devices, then the mobile device's location can be determined, but the estimation accuracy is poor due to large areas of uncertainty
Solution Approach 1:
The patent replaces the conventional trilateration method (geometric intersection of circles) with an annular area overlap method. Instead of estimating position at the intersection point of three circles, the system creates annular areas (rings) around each in-vehicle device based on reception signal intensity, then determines the mobile device's position in the overlapping region of these annular areas. This substitution fundamentally changes the estimation approach from point-based to area-based, improving accuracy by reducing the uncertainty area.
Solution Approach 2:
The patent changes the parameter used for position estimation from direct distance measurement (radius of circles) to reception signal intensity ranges (annular areas). By using signal intensity thresholds to define annular regions rather than precise radial distances, the system accounts for signal variability and reduces estimation uncertainty. The mobile device's position is estimated in the overlapping area of multiple annular regions, providing more robust and accurate location determination.
2Measurement precision
If multiple annular areas are created to reduce detection uncertainty, then position estimation accuracy improves, but the system complexity increases
Solution Approach 1:
The patent segments the detection space into multiple annular areas, each centered on an in-vehicle device. Instead of using a single complex geometric construction, the system divides the problem into simpler components: creating individual annular regions around each transmitter based on signal intensity thresholds. The mobile device's position is then determined by finding the overlapping region of these segmented annular areas, which simplifies the overall computational approach while improving accuracy.
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
This system improves position estimation accuracy by reducing the area where the mobile device is estimated to exist, allowing for more precise location determination and enabling accurate execution of processes such as vehicle engine starting and door unlocking.
Implementation Method 1
an in-vehicle device 100 including at least three in-vehicle antennas 191F, 191R, 191B, 191L that may transmit an electric wave
Implementation Method 2
a reception intensity detection portion that may detect a reception signal of the electric wave
Data Source
AI summary
A mobile device position estimation system includes: an in-vehicle device that includes at least three in-vehicle antennas that transmits an electric wave; and a mobile device. The mobile device includes a reception intensity detection portion that detects a reception signal of the electric wave. The in-vehicle device or the mobile device includes a sensitivity error decision portion that decides a reception sensitivity error to cause multiple mobile device detection areas to be closest to a state where the multiple mobile device detection areas intersect at one point while deciding mobile device detection areas, an annular area decision portion that decides multiple annular areas where the mobile device exists, and a mobile device area estimation portion that estimates an overlapping area where the multiple annular areas overlap as a mobile device existence area.