Evaluation of Mobile Environment for Vehicular Visible Light Communication Using Multiple LEDs and Event Cameras
Ryota Soga, Shintaro Shiba, Quan Kong, Norimasa Kobori, Tsukasa Shimizu, Shan Lu, Takaya Yamazato
TL;DR
This work addresses the bottleneck of RF congestion for vehicle-to-everything communication by enabling visible-light communication using an event camera as the receiver. It introduces a Walsh-Hadamard code-based pilot-sequence scheme to identify and separate multiple LED clusters and a vibration-correction algorithm to maintain alignment in motion. Field experiments demonstrate error-free communication up to 40–55 meters at speeds up to 30–40 km/h, with data rates in the tens of kbps, illustrating the viability of event-camera VLC as a practical vehicular sensor. The study highlights the potential for high-temporal-resolution, camera-based V2X sensing while outlining future directions to improve speed adaptability and distance via more efficient pilots and stronger error-correcting codes.
Abstract
In the fields of Advanced Driver Assistance Systems (ADAS) and Autonomous Driving (AD), sensors that serve as the ``eyes'' for sensing the vehicle's surrounding environment are essential. Traditionally, image sensors and LiDAR have played this role. However, a new type of vision sensor, event cameras, has recently attracted attention. Event cameras respond to changes in the surrounding environment (e.g., motion), exhibit strong robustness against motion blur, and perform well in high dynamic range environments, which are desirable in robotics applications. Furthermore, the asynchronous and low-latency principles of data acquisition make event cameras suitable for optical communication. By adding communication functionality to event cameras, it becomes possible to utilize I2V communication to immediately share information about forward collisions, sudden braking, and road conditions, thereby contributing to hazard avoidance. Additionally, receiving information such as signal timing and traffic volume enables speed adjustment and optimal route selection, facilitating more efficient driving. In this study, we construct a vehicle visible light communication system where event cameras are receivers, and multiple LEDs are transmitters. In driving scenes, the system tracks the transmitter positions and separates densely packed LED light sources using pilot sequences based on Walsh-Hadamard codes. As a result, outdoor vehicle experiments demonstrate error-free communication under conditions where the transmitter-receiver distance was within 40 meters and the vehicle's driving speed was 30 km/h (8.3 m/s).