Time Synchronization Scheme of Underwater Platforms Using Wireless Acoustic and Optical Communication

Time synchronization in autonomous underwater vehicle (AUV) formations is significant for joint underwater survey tasks. Maintaining a common time scale can improve the efficiency of cooperative localization, formation control, and data fusion. Instead of using atomic clocks to limit the offset and drift of time, we propose an acoustic and optical cooperative method to synchronize the clocks. Acoustic communication is used to guide the establishment of the optical link and to share the states of the AUVs, while optical communication is used to measure the time difference between the clocks of the two AUVs. The field experiments demonstrated that our proposed method can perform time synchronization in real scenarios.