expected to benefit from the system as early as mid 2021.
VLC is already used in office, home and laboratory environments. In factory environments, however, the hurdles for communication technology are high or have not yet been sufficiently researched due to the particular disruptive factors. "As an alternative to conventional wireless network access, we will use commercially available, energy-efficient LEDs for VLCs," explains Schneider. Such a system can be considered reliable if coverage problems caused by walls, metallic objects, machines and other interfering signals can be overcome. Artificial light sources, shadows and reflections can affect data transmission via light. The systematic detection and quantification of these influences is a sub-task of the project. The measurement campaign focused on a total of three influencing variables: Ambient light sources, particles and ambient reflections (multipath propagation).
The tests so far proved that dust particles do not pose a problem for optical signals, since today's factory buildings are usually well ventilated. Even persons and vehicles moving slowly at 0.2 m/s have little effect on the quality of the signal. Ambient light sources, on the other hand, interfere with data transmission, and this over the entire optical spectrum. The project partners have identified a total of ten models to whose lighting conditions VLC systems react. These include welding processes and fluorescent tubes, but also optical tracking systems. However, they only occur locally and not across locations. VLC systems, and this is one of the results of the tests, must therefore be able to react adaptively to the lighting conditions and minimise such disturbing influences.