*Article* **Visible Light Communication System for O** ff**shore Wind Turbine Foundation Scour Early Warning Monitoring**

#### **Yung-Bin Lin 1,\*, Tzu-Kang Lin 2, Cheng-Chun Chang 3, Chang-Wei Huang 4, Ben-Ting Chen 1, Jihn-Sung Lai 5 and Kuo-Chun Chang 1**



 **\*** Correspondence: yblin@narlabs.org.tw

Received: 4 June 2019; Accepted: 11 July 2019; Published: 17 July 2019

**Abstract:** O ffshore wind farms have a superior wind source to terrestrial wind farms, but they also face more severe environmental conditions such as severe storms, typhoons, and sea waves. Scour leads to the excavation of sediments around the foundations of structures, reducing the safe capacity of the structures. The phenomenon of pier scour is extremely complex because of the combined e ffects of the vortex system involving time-dependent flow patterns and sediment transport mechanisms. A real-time scour monitoring system can improve the safety of structures and a fford cost-e ffective operations by preventing premature or unnecessary maintenance. This paper proposes an on-site scour monitoring system using visible light communication (VLC) modules for o ffshore wind turbine installations. A flume experiment revealed that the system was highly sensitive and accurate in monitoring seabed scour processes. This arrayed-VLC sensory system, proposed in this paper, has considerable potential for safety monitoring and also can contribute to improving the accuracy of empirical scour formulas for sustainable maintenance in the life cycle of o ffshore structures.

**Keywords:** visible light communication system; o ffshore wind turbine foundation; scour; early warning monitoring; life cycle
