Indoor Illumination Positioning via Modulated Light Triangulation
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Solution Overview
Problem
Conventional RFID position measurement methods require a large number of readers due to limited detection range, resulting in high costs and inability to determine precise object positions within indoor spaces.
Innovation Solution
An indoor illuminating apparatus with a lattice or matrix arrangement of light sources that output modulated light signals, allowing a portable terminal to calculate its position based on reference light source information and reception times using triangulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional RFID readers are used for position measurement, then detection range is limited, but the number of readers required increases, resulting in high cost and system complexity
Solution Approach 1:
The patent merges the illumination function and position measurement function into a single integrated system. Indoor illuminating apparatus that normally emit light are modified to also transmit position measurement signals by modulating the light intensity according to data frames containing position information. This eliminates the need for separate RFID readers while achieving precise position measurement through triangulation using multiple illuminating apparatus.
Solution Approach 2:
The illuminating apparatus are given dual functionality: they serve both as normal lighting sources and as position measurement transmitters. By encoding position data into light intensity modulation, the same physical infrastructure (illuminating apparatus already present in the space) performs both illumination and positioning tasks, reducing system complexity and cost.
2Measurement precision
If conventional RFID readers are used for position measurement, then detection range is limited, but more readers are needed, resulting in high installation cost
Solution Approach 1:
The system utilizes existing illuminating apparatus that are already installed in the indoor space for the dual purpose of illumination and position measurement. No additional dedicated positioning infrastructure needs to be installed - the existing lighting system serves itself by incorporating position measurement capabilities through light intensity modulation, significantly reducing installation cost.
Solution Approach 2:
The patent combines position measurement functionality with existing illuminating apparatus, eliminating the need for separate positioning infrastructure. By modulating the light output of existing fixtures to encode position data frames, the system achieves precise positioning without additional installation costs for dedicated readers or transmitters.
3Reliability
If conventional RFID method is used, then object detection is possible, but definite position recognition is not achieved
Solution Approach 1:
The patent replaces the RFID electromagnetic wave-based detection system with an optical system using visible light from illuminating apparatus. By modulating light intensity to carry position data frames and using triangulation geometry, the system achieves precise definite position recognition rather than just detection zone identification, maintaining reliability while improving measurement precision.
Solution Approach 2:
The system transitions from RFID's signal-based detection to optical triangulation by introducing spatial dimensionality through multiple illuminating apparatus at different positions. The portable terminal calculates its position by analyzing arrival times or signal characteristics from multiple light sources, achieving precise 2D or 3D position recognition through geometric relationships rather than simple detection zone assignment.
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 precise and cost-effective position measurement of portable terminals within indoor spaces without the need for additional components, reducing the complexity and expense of the positioning system.
Implementation Method 1
a plurality of light sources for outputting light according to separately input driving signals
Implementation Method 2
detecting indoor illuminating light and outputting an electric signal corresponding to the detected indoor illuminating light
Data Source
AI summary
Provided is a method of measuring the position of a portable terminal, comprising detecting indoor illuminating light, and outputting an electric signal corresponding to the detected indoor illuminating light, obtaining a plurality of data frames from the output electrical signal, and calculating a position of the portable terminal based on information regarding the position of a corresponding reference light source included in each data frame and an identifier corresponding to the reference light source included in said each frame and a reception time of said each data frame.