Single LED visible light positioning system based on image sensor and calculated azimuth angle

Area of Science:

• Optical engineering
• Indoor positioning systems
• Computer vision

Background:

• Visible Light Positioning (VLP) systems offer a promising alternative for indoor localization.
• Existing VLP systems often rely on magnetometers for accurate azimuth estimation, which can be susceptible to interference.
• Smartphone cameras are ubiquitous, making camera-based VLP systems highly accessible.

Purpose of the Study:

• To propose and demonstrate a novel single-lamp Visible Light Positioning (VLP) system utilizing a standard smartphone camera.
• To enhance azimuth angle accuracy by employing a marked lamp bead, eliminating the need for a magnetometer.
• To introduce an improved VLP positioning algorithm based on image plane chords.

Main Methods:

• A VLP system was designed using a circular light-emitting diode (LED) for data transmission and a smartphone camera for image acquisition.
• A new scheme for azimuth angle calculation was developed using a marked lamp bead on the LED.
• A novel positioning method was implemented using image plane chords passing through midpoints of parallel chords.

Main Results:

• The proposed system successfully demonstrated VLP using a single LED and a smartphone camera.
• The azimuth angle calculation method, without a magnetometer, improved positioning accuracy.
• In an experimental area of 1.8m x 3.6m, 3D positioning errors were as low as 7.2 cm at a height of 1.2m.

Conclusions:

• The developed single-lamp VLP system provides accurate 3D positioning using readily available hardware.
• The novel azimuth calculation and image plane chord methods significantly enhance VLP performance.
• This approach offers a practical and accurate solution for indoor localization applications.