First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements. Researchers are therefore investigating applications for mobile robots and robotic tools that are networked with artificial intelligence in the cloud for the so-called Internet of Things (IoT). Wireless data transmission is essential for this, but must be just as reliable and at low-latency as a wired data connection. Li-Fi is based on low-cost LEDs and uses the license-free spectrum of visible and infrared light. Optical data transmission does depend on a line-of-sight connection, however, it cannot be jammed by radio transmitters.

“The Li-Fi solution based on a Multiple-Input Multiple-Output (MIMO) architecture enables reliable mobile communication in production processes, with especially low latency,” comments Dr. Volker Jungnickel, project coordinator at Fraunhofer HHI, on the developments.

“Li-Fi can unburden the densely occupied Wi-Fi spectrum and realize an uninterrupted mobile transmission for industrial IoT. Li-Fi works reliably when typical industrial work such as spot welding with high currents and flashes of light takes place,” emphasizes Gerhard Kleinpeter, project manager at BMW.

The three-year project was funded by the Federal Ministry of Education and Research (BMBF) with 1.6 million euros. Project partners were BMW AG, evopro and Fraunhofer HHI (coordinator). OSRAM and the Munich University of Applied Sciences were associated partners and subcontractors, respectively. The project work on the industrial Li-Fi system was presented through demonstrations and scientific publications at international trade fairs and conferences, such as the Hanover Fair, ECOC, OFC and WCNC, and contributed significantly to standardization (IEEE P802.15.13 and P802.11bb, ITU-T G.vlc).