Visible light positioning (VLP) is a promising technology since it can provide high accuracy indoor localization based on the existing lighting infrastructure. However, existing approaches often require dense LED distributions and persistent line-of-sight (LOS) between transmitter and receiver. What's more, sensors are imperfect, and their measurements are prone to errors. Through multi sensors fusion, we can compensate the deficiencies of stand-alone sensors and provide more reliable pose estimations. In this work, we propose a loosely-coupled multi-sensor fusion method based on VLP and Simultaneous Localization and Mapping (SLAM), using light detection and ranging (LiDAR), odometry, and rolling shutter camera. Our multi-sensor localizer can provide accurate and robust robot localization and navigation in LED shortage/outage situations. The experimental results show that our proposed scheme can provide an average accuracy of 2.5 cm with around 42 ms average positioning latency.

Indoor robotic localization is one of the most active areas in robotics research nowadays. Visible light positioning (VLP) is a promising indoor localization method, as it provides high positioning accuracy and allows for leveraging the existing lighting infrastructure. Apparently, accurate positioning performance is mostly shown by the VLP system with multiple LEDs, while such strict requirement of LED numbers is more likely to lead to VLP system failure in actual environments. In this paper, we propose a single-LED VLP system based on image sensor with the help of angle sensor estimation, which efficiently relaxes the assumption on the minimum number of simultaneously captured LEDs from several to one. Aiming at improving the robustness and accuracy of positioning in the process of continuous change of robot pose, two methods of visual-inertial message synchronization are proposed and used to obtain the well-matched positioning data packets. Various schemes of single-LED VLP system based on different sensor selections and message synchronization methods have been listed and compared in an actual environment. The effectiveness of the proposed single-LED VLP system based on odometer and image sensor as well as the robustness under LED shortage, handover situation and background non-signal light interference, are verified by real-world experiments. The experimental results show that our proposed system can provide an average accuracy of 2.47 cm and the average computational time in low-cost embedded platforms is around 0.184 s.

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For mobile robots and location-based services, precise and real-time positioning is one of the most basic capability, and low-cost positioning solutions are increasingly in demand and have broad market potential. In this paper, we innovatively design a high-accuracy and real-time indoor localization system based on visible light positioning (VLP) and mobile robot. First of all, we design smart LED lamps with VLC and Bluetooth control functions for positioning. The design of LED lamps includes hardware design and Bluetooth control. Furthermore, founded on the loose coupling characteristics of ROS (Robot Operator System), we design a VLP-based robot system with VLP information transmitted by designed LED, dynamic tracking algorithm of high robustness, LED-ID recognition algorithm, and triple-light positioning algorithm. We implemented the VLP-based robot positioning system on ROS in an office equipped with the designed LED lamps, which can realize cm-level positioning accuracy of 3.231 cm and support the moving speed up to 20 km/h approximately. This paper pushes forward the development of VLP application in indoor robots, showing the great potential of VLP for indoor robot positioning.

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