Visible Light Positioning With Lam\'e Curve LEDs: A Generic Approach for Camera Pose Estimation

2026-02-02

AI Summary

This work addresses the performance degradation of existing visible light positioning (VLP) methods in heterogeneous LED environments, where reliance on a single LED geometric shape limits robustness. To overcome this limitation, the authors propose LC-VLP, a general-purpose localization algorithm that, for the first time, employs Lamé curves to unify the modeling of diverse LED shapes. An offline database is constructed by integrating visible light communication parameters, and online camera pose estimation is achieved through nonlinear least-squares optimization. A novel FreePnP initialization scheme is introduced, eliminating the need for feature point matching and thereby enhancing robustness in heterogeneous LED settings. Experimental results demonstrate that the proposed method reduces position and orientation errors by over 40% and 25%, respectively, in simulations, and achieves an average real-world localization accuracy better than 4 cm.

Technology Category

• Intelligent Robots: Localization, Mapping, and Navigation
• Computer Vision: Language and Vision
• Search and Optimization: Learning to Search

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs
• Responsible Web: Human-perceived consequences of algorithmic deployment on the web

Abstract

Camera-based visible light positioning (VLP) is a promising technique for accurate and low-cost indoor camera pose estimation (CPE). To reduce the number of required light-emitting diodes (LEDs), advanced methods commonly exploit LED shape features for positioning. Although interesting, they are typically restricted to a single LED geometry, leading to failure in heterogeneous LED-shape scenarios. To address this challenge, this paper investigates Lam\'e curves as a unified representation of common LED shapes and proposes a generic VLP algorithm using Lam\'e curve-shaped LEDs, termed LC-VLP. In the considered system, multiple ceiling-mounted Lam\'e curve-shaped LEDs periodically broadcast their curve parameters via visible light communication, which are captured by a camera-equipped receiver. Based on the received LED images and curve parameters, the receiver can estimate the camera pose using LC-VLP. Specifically, an LED database is constructed offline to store the curve parameters, while online positioning is formulated as a nonlinear least-squares problem and solved iteratively. To provide a reliable initialization, a correspondence-free perspective-\textit{n}-points (FreeP\textit{n}P) algorithm is further developed, enabling approximate CPE without any pre-calibrated reference points. The performance of LC-VLP is verified by both simulations and experiments. Simulations show that LC-VLP outperforms state-of-the-art methods in both circular- and rectangular-LED scenarios, achieving reductions of over 40% in position error and 25% in rotation error. Experiments further show that LC-VLP can achieve an average position accuracy of less than 4 cm.

Problem

• Visible Light Positioning
• Camera Pose Estimation
• LED Shape Heterogeneity
• Indoor Localization
• Lamé Curve

Innovation

• Lamé curve
• visible light positioning
• camera pose estimation
• generic LED modeling
• FreePnP